Answers.Body: <p>The answer I've <a href="https://bricks.stackexchange.com/a/420/3631">heard</a> the <a href="https://soranews24.com/2015/06/12/theres-a-reason-why-there-are-fewer-green-lego-bricks-than-any-other-color" rel="noreferrer">most</a> (with a <a href="https://www.zmescience.com/other/did-you-know/lego-military-toys" rel="noreferrer">source citing the official confirmation</a>) is that green, brown and gray bricks were omitted from the LEGO palette because the company wanted to discourage kids from building tanks, planes, and other realistic military hardware.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T10:19:42.907Z
Answers.Text: Wow. Never thought of this one, though when enumerating the colours as "green, brown and gray", the possible connection to camouflage becomes immediately obvious.
Answers.UserDisplayName: O. R. Mapper
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T12:47:26.480Z
Answers.Text: There is some [further evidence to this theory](https://www.zmescience.com/other/did-you-know/lego-military-toys/).
Answers.UserDisplayName: T. Sar
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T13:19:06.157Z
Answers.Text: @T.Sar-ReinstateMonica TLG's reluctance to produce realistic, modern military equipment is clear and well known, but as far as I can see, the linked article does not mention the connection between this phenomenon and the lack of specific colours, asked by OP.
Answers.UserDisplayName: zovits
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T13:39:16.257Z
Answers.Text: That article doesn't connect to the color, yes, but it gives a reference for those that weren't aware of this reluctance from part of TLG. I, for one, wasn't aware of it.
Answers.UserDisplayName: T. Sar
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T14:28:06.120Z
Answers.Text: Though they had no problem including various types of guns (both in the space and pirate sets), and even working cannons (though they sadly backtracked on that one later).  There was also an extensive variety of medieval weapons in the castle sets.  So - ancient and futuristic weapons are okay, but modern ones aren't?
Answers.UserDisplayName: Darrel Hoffman
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T15:26:12.067Z
Answers.Text: @DarrelHoffman This is more like a general guideline, not a strict rule. [The official statement](https://bricks.stackexchange.com/a/294/3631) says "The basic aim is to avoid realistic weapons and military equipment that children may recognize from hot spots around the world and to refrain from showing violent or frightening situations". However, LEGO has produced sets depicting all of the above, but every time the focus is either in the model itself, like in the case of [Sopwith Camel](https://brickset.com/sets/3451-1/Sopwith-Camel) or [part 1 of 2, continued below]
Answers.UserDisplayName: zovits
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T15:34:07.540Z
Answers.Text: [continued] or the interaction between well-defined good and bad actors, like in some [Indiana Jones sets](https://brickset.com/sets/7625-1/River-Chase), or the militaristic personnel and equipment is an integral part of an otherwise kid-friendly franchise, like [Toy Story](https://brickset.com/sets/7595-1/Army-Men-on-Patrol) or [Lone Ranger](https://brickset.com/sets/79106-1/Cavalry-Builder-Set). Note though, that TLG has produced historical realistic fighter planes even outside of licenced themes, like [in Pharaoh's Quest](https://brickset.com/sets/7307-1/Flying-Mummy-Attack). [part 2 of 2]
Answers.UserDisplayName: zovits
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-18T03:05:39.113Z
Answers.Text: I have to say, the lack of colours *never* stopped me from producing machines of war.  You should have seen my bedroom the day after I sneakily saw Top Gun......
Answers.UserDisplayName: Moo
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-18T07:38:04.143Z
Answers.Text: Brown dogs/horses and green trees/grass/plants were quite  acceptable then, so it must have been more targetted to bricks.
Answers.UserDisplayName: Criggie
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-18T07:43:16.703Z
Answers.Text: @Criggie Right, but don't forget, the plant pieces were made of polyethylene instead of ABS, which made them softer and more pliable. However, the existence of the green "baseplate" brick mentioned in [a comment by shoover](https://bricks.stackexchange.com/questions/12940/why-was-lego-reluctant-to-use-additional-colours-for-regular-bricks-in-former-ti/12944?noredirect=1#comment15275_12940) above proves that green ABS was indeed used, just not for basic bricks.
Answers.UserDisplayName: zovits
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-18T19:09:17.640Z
Answers.Text: This justification was also used in the documentary [The Toys That Made Us](https://www.netflix.com/title/80161497).
Answers.UserDisplayName: Phil Frost
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T09:26:14.423Z
Answers.LastActivityDate: 2020-02-17T12:57:21.267Z
Answers.LastEditDate: 2020-02-17T12:57:21.267Z
Answers.UserDisplayName: zovits
Answers.Body: <p>I have a background in precision injection moulding, although not to the extremely tight tolerances of Lego. Here's why a manufacturer would try to reduce the number of colours they used, particularly in the old days.</p>
  
  <p>Most resin (the raw material) nowadays comes pre-coloured, especially for a large customer like Lego. That wasn't the case fifty or sixty years ago: we used to get white resin and colour it with powdered pigment. This operation would have to be repeated for each batch of each colour, a batch being (in the old days) a cement mixer's worth of resin. Between colours you would need to clean the mixer out thoroughly, because a small amount of the wrong pigment could contaminate many pieces. The contamination would be hard to see: try examining 1,000 pieces for a small swirl of the wrong colour!</p>
  
  <p>If the colour of a moulded piece was off we would have to re-grind it, add more pigment / plain resin and re-mould it. We couldn't do that for pieces of different colours, or for badly contaminated pieces. We had the advantage of manufacturing some products in black that would hide most discolourations, so we would reserve contaminated material for those.</p>
  
  <p>Moulding machines used to have a hopper above the machine, and the coloured resin would literally be carried up a ladder and poured inside. To switch between colours we would generally run the hopper until it was almost empty, possibly add some plain or disposable reground material to "purge" it, and then add the new material. A certain amount of pieces would necessarily be contaminated by the old colour, which meant that changing colours for small batches could be quite wasteful. Nowadays we have vacuum feeders instead of large hoppers. We still have the problem of colour contamination, but this has been reduced by better mould design.</p>
  
  <p>Speaking of moulds, older moulds used to convey the plastic down a channel to the moulds for the individual pieces. When the mould emptied the channels, called sprues, would separate or be sepaarated from the puieces and reground. There would invariably be a certain amount of this material left at the end of a job, and it could be a pain keeping track of it for next time.  </p>
  
  <p>When you add these costs in time/quality together it's easy to see that (keeping the total number of pieces constant) adding extra colours rapidly increases your overheads. It isn't just the fixed cost of changeover and storage, but the potential for things going wrong. I think this would have given Lego a good reason to reduce the number of colours they used, particularly when the firm was smaller and technology wasn't as advanced.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-19T03:57:19.303Z
Answers.Text: Thanks for this detailed answer, and welcome to Bricks.SE!
Answers.UserDisplayName: jncraton
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-02-17T13:44:57.847Z
Answers.Text: LEGO used to produce bricks from pre-coloured raw material, however they've switched base+color pellets nowadays. I'm not entirely sure why (probably due to cost saving), but this introduced problems with color consistency, which is still hasn't been resolved until today.
Answers.UserDisplayName: Alex
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-19T03:41:50.723Z
Answers.LastActivityDate: 2019-12-19T03:41:50.723Z
Answers.UserDisplayName: Joe Slater
Answers.Body: <p>A practical engineering concern could be a reason to limit the colours used for molding in ABS plastic.</p>
  
  <p>The colourant added to the base plastic can affect the physical properties of the molded part. Depending on how tight the dimensional tolerances are for the finished part a separate mold may be required for each colour.</p>
  
  <p>Perhaps the Lego group process engineers have enough controls in the automated molding process now to tweak the mold setups to compensate for the variations induced by the colourants.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T08:24:16.367Z
Answers.Text: You may be on to something there, given that the early swords may indeed be somewhat softer, as were various of the earlier green pieces ([old trees](http://www.peeron.com/inv/parts/3470) and [whips](http://www.peeron.com/inv/parts/2488), for example - but obviously not the plates), pointing to differences in the material. Do you have any references to back this up?
Answers.UserDisplayName: O. R. Mapper
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T13:15:42.477Z
Answers.Text: @O.R.Mapper I'm fairly sure those pieces were deliberately made in softer material to be slightly movable, to avoid breaking. They're generally things containing longer or thinner pieces that would easily be subjected to accidental damaging force. I doubt this is related to the colour.
Answers.UserDisplayName: Nyerguds
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T20:05:45.623Z
Answers.Text: @Nyerguds: Certainly. In the case of whips, for instance, they are intentionally softer as they are *meant* to be bent for some sets. I rather thought of it the other way round: Maybe certain colours were somehow easier or cheaper to manufacture with soft materials, so they were used for parts that were always manufactured from softer material in the regular colours, as well.
Answers.UserDisplayName: O. R. Mapper
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T02:40:19.020Z
Answers.LastActivityDate: 2019-12-17T02:40:19.020Z
Answers.UserDisplayName: Dan1138
Answers.Body: <p>Early LEGO colors were inspired by the work of Mondriaan, which mainly consists of white, black, red, blue and yellow. These primary colors were considered to be most appealing to kids.</p>
  
  <p><a href="https://i.sstatic.net/UKhW0.jpg" rel="noreferrer"><img src="https://i.sstatic.net/UKhW0.jpg" alt="enter image description here"></a></p>
  
  <p>From the book <a href="https://rads.stackoverflow.com/amzn/click/com/0307951618" rel="noreferrer" rel="nofollow noreferrer">“Brick by Brick”</a>: </p>
  
  <blockquote>
    <p>The new product was patented in 1958 and within a few years bright
    yellow, red and blue Lego bricks, colours inspired by the paintings of
    the Dutch Modernist painter Piet Mondrian, were scattered across the
    floors of millions of homes.</p>
  </blockquote>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T08:19:58.040Z
Answers.Text: Interesting, but is this just speculation, or do you have any references to back this up?
Answers.UserDisplayName: O. R. Mapper
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T10:51:35.143Z
Answers.Text: From the book “Brick by Brick”:  The new product was patented in 1958 and within a few years bright yellow, red and blue Lego bricks, colours inspired by the paintings of the Dutch Modernist painter Piet Mondrian, were scattered across the floors of millions of homes.
Answers.UserDisplayName: Phil B.
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-18T03:18:36.420Z
Answers.Text: @Keeta-reinstateMonica Done!
Answers.UserDisplayName: Phil B.
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-18T04:55:49.437Z
Answers.Text: Does *Brick by Brick* indicate in any way **their** source for this? The use of primary colors in kids’ products is pretty wide-spread, and I have doubts that Piet was the direct inspiration for that in a variety of settings. Something from LEGO themselves would seem necessary to cement this claim.
Answers.UserDisplayName: KRyan
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-19T12:57:13.530Z
Answers.Text: This justification was also used in the documentary [The Toys That Made Us](https://www.netflix.com/title/80161497).
Answers.UserDisplayName: Amedee Van Gasse
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-19T21:50:56.107Z
Answers.Text: I did not realize there was a link between LEGOs and The Partridge Family.  Wow.
Answers.UserDisplayName: Monty Harder
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T01:38:30.627Z
Answers.LastActivityDate: 2019-12-18T03:18:04.367Z
Answers.LastEditDate: 2019-12-18T03:18:04.367Z
Answers.UserDisplayName: Phil B.
Answers.Body: <p>Manufacturing logistics play a part in this decision. If you have to maintain six different dyes or pellet hopper combinations in the injection molding pipeline in your factory, that is a different story in terms of cost than maintaining sixteen or thirty hopper combinations or dye vats. If the pellets are pre-dyed (as I believe was the case), sourcing these will depend on the logistics of and the options made available by the supplier.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-18T07:27:34.160Z
Answers.Text: It's [known](https://bricks.stackexchange.com/q/8543/3631) that LEGO has had problems sourcing red and yellow colours that did not contain cadmium, but no such problems have been known about green, brown or grey.
Answers.UserDisplayName: zovits
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-18T07:44:26.637Z
Answers.Text: Also, the existence of the green "baseplate" brick mentioned in [a comment by shoover above](https://bricks.stackexchange.com/questions/12940/why-was-lego-reluctant-to-use-additional-colours-for-regular-bricks-in-former-ti/12944?noredirect=1#comment15275_12940) proves that green ABS was indeed used, just not for basic bricks.
Answers.UserDisplayName: zovits
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-17T19:38:56.723Z
Answers.LastActivityDate: 2019-12-17T19:38:56.723Z
Answers.UserDisplayName: pygosceles
Answers.Body: <p>Most bricks in sets are picked from large bins of a given colour/shape when making up a set, and used in many different sets.  Hence there is a cost advantage to limiting the number of colours and hence the number of different brick. </p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-18T19:56:25.730Z
Answers.Text: So, why did (the importance of?) that cost advantage gradually change or vanish starting toward the end of the 1980s?
Answers.UserDisplayName: O. R. Mapper
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-19T15:07:20.610Z
Answers.Text: @O.R.Mapper I **expect** automatic systems for picking bricks from many bins,  and increased production levels.   Along with them wishing to create more realistic models.
Answers.UserDisplayName: Ian Ringrose
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-18T16:46:04.220Z
Answers.LastActivityDate: 2019-12-18T16:46:04.220Z
Answers.UserDisplayName: Ian Ringrose
Body: <p>Looking back to what LEGO offered in the 1980s and early 1990s (oh, those memories ...), it looks a lot like LEGO's colour palette had been limited to a small number of colours - unless I'm missing something, and just counting non-transparent colours now, mostly:</p>
  
  <ul>
  <li>white</li>
  <li>black</li>
  <li>red</li>
  <li>blue</li>
  <li>yellow</li>
  <li>light grey</li>
  </ul>
  
  <p>But wait: A couple of other colours had been around for a long time, but had only been used for quite special elements for many years:</p>
  
  <ul>
  <li>dark gray (some other castle accessories, such as minifig <a href="http://www.peeron.com/inv/sets/6075-2" rel="noreferrer">swords</a>, at least since <a href="http://www.peeron.com/inv/sets/6075-2" rel="noreferrer">1981</a> ... before the colour started getting slightly more widespread in actual buildings in the shape of BURPs, starting in <a href="http://www.peeron.com/inv/sets/6076-1" rel="noreferrer">1993</a>)</li>
  <li>brown (some castle accessories, such as minifig <a href="http://www.peeron.com/inv/parts/4497" rel="noreferrer">spears</a> or <a href="http://www.peeron.com/inv/parts/4499" rel="noreferrer">bows with arrows</a>, at least since <a href="http://www.peeron.com/inv/sets/6073-1" rel="noreferrer">1984</a> ... until LEGO finally started using some brown for trees instead of approximating them with black around <a href="http://www.peeron.com/inv/sets/6552-1" rel="noreferrer">1993</a>)</li>
  <li>green (granted, this one appeared as plates in castle sets at least since <a href="http://www.peeron.com/inv/sets/6073-1" rel="noreferrer">1984</a>, but was otherwise mostly reserved to plant parts, baseplates, and special decorative elements such as <a href="http://www.peeron.com/inv/parts/4495" rel="noreferrer">flags</a> ... until around 1992, when the fictional Octan gasoline brand was introduced and green started becoming a "mainstream" colour)</li>
  </ul>
  
  <p>Now, I am aware I have not listed all the parts that ever came in the respective colours; my point is that, at least in my impression, these three colours listed above were mainly used for a rather small number of accessories or other specific elements for many years, as opposed to seeing widespread use as regular plates and bricks, compared to the other aforementioned colours.</p>
  
  <p><strong>Is there any known reason in terms of business/design decisions/the material used for each of the colours for this?</strong></p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-17T04:51:07.377Z
Comments.Text: The actual light grey is actually a fairly rare color. The lighter of the 2 common greys is actually medium grey, with light grey appearing only rarely (in sets like Thok and King Mathias).
Comments.UserDisplayName: Alexander O'Mara
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-17T10:53:25.490Z
Comments.Text: @AlexanderO'Mara: and in certain NXT components.
Comments.UserDisplayName: Phil B.
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-17T12:49:07.053Z
Comments.Text: This doesn’t detract from your main point, but Lego had “started using some brown for trees” already by 1989, in the palm trees of the Pirates sets, eg [Forbidden Island](http://www.peeron.com/inv/sets/6270-1).  As you say, though, this was still specialised pieces, not ordinary blocks.
Comments.UserDisplayName: Peter LeFanu Lumsdaine
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-17T12:52:06.197Z
Comments.Text: @PeterLeFanuLumsdaine: Right, "brown for trees" was an oversimplification. Pirates also brought brown ship hulls, brown ship ladders, brown oars, and some more pieces like the small wooden barrels had probably been around in Castle even a bit earlier. But, yes, this arguably makes it even more noteworthy that of all pieces, standard bricks in these colours were conspicuously absent, especially considering that Pirates *did* feature other wooden structures where wood was mimicked with black pieces (parts of pirate buildings, the crane on the imperial palace, etc.).
Comments.UserDisplayName: O. R. Mapper
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-17T13:51:12.173Z
Comments.Text: I recall green flat 2x3 in the 1970s.
Comments.UserDisplayName: chux
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-17T14:05:52.590Z
Comments.Text: @chux-ReinstateMonica: The earliest occurrence listed on [Peeron](http://www.peeron.com/inv/parts/3021?color=Green) is from 1984. Or do you mean a different part?
Comments.UserDisplayName: O. R. Mapper
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-17T14:29:10.853Z
Comments.Text: Set 125 in 1974 had a [10x20 green brick](https://www.bricklink.com/v2/catalog/catalogitem.page?P=700eD&idColor=6#T=C&C=6). It was one brick tall and had connecting tubes around the bottom edge, so it's technically a brick.
Comments.UserDisplayName: shoover
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-18T02:18:36.027Z
Comments.Text: Here's an interesting, slightly relevant tidbit: maroon and to a lesser degree brown LEGOs are much more brittle than others. Try assembling an old Luke's Landspeeder set without pieces breaking on you.
Comments.UserDisplayName: Nonny Moose
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-18T06:35:31.780Z
Comments.Text: Bear in mind that the greys used in sets older than 2002 are different to modern greys.  Lego changed the colour palette in the early 00s to make the colours more child friendly and the biggest change were the greys, which were given a blue rather than brown hue.  The colour change is so dramatic that you basically can't use the two side by side in a model.  The browns were changed as well but the change was not as dramatic.
Comments.UserDisplayName: Stephen
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-18T06:58:32.587Z
Comments.Text: @Stephen: I read about that, but it seems irrelevant here: The colours I list were around in special parts since the 1980s and gradually started appearing as regular bricks in tbe course of the 1990s.
Comments.UserDisplayName: O. R. Mapper
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-18T07:00:32.627Z
Comments.Text: @shoover: Technically true, as you say, though "bricks" of that size are, in their possible use cases, much like "thick plates" rather than what I referred to as "regular bricks" (that are suited to build a plain wall, for example).
Comments.UserDisplayName: O. R. Mapper
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-18T09:35:45.870Z
Comments.Text: I recently saw an episode of a tv show "The Toys that made us" regarding Lego. It did include some of the decisions they made (including used colors). Might be an interesting watch to get an idea why/what kind of decisions the company made.
Comments.UserDisplayName: Bart de Ruijter
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-27T10:04:12.080Z
Comments.Text: @O.R.Mapper Are you waiting on additional information or is there something else preventing you from accepting an answer?
Comments.UserDisplayName: zovits
Tags: <history><colour>
Title: Why was LEGO reluctant to use additional colours for regular bricks in former times?
UserDisplayName: O. R. Mapper
ThreadText: # Why was LEGO reluctant to use additional colours for regular bricks in former times?
  
  (Asked by: username_0 on 2019-12-16)
  
  Looking back to what LEGO offered in the 1980s and early 1990s (oh, those memories ...), it looks a lot like LEGO's colour palette had been limited to a small number of colours - unless I'm missing something, and just counting non-transparent colours now, mostly:
  
  * white
  * black
  * red
  * blue
  * yellow
  * light grey
  
  But wait: A couple of other colours had been around for a long time, but had only been used for quite special elements for many years:
  
  * dark gray (some other castle accessories, such as minifig [swords](http://www.peeron.com/inv/sets/6075-2), at least since [1981](http://www.peeron.com/inv/sets/6075-2) ... before the colour started getting slightly more widespread in actual buildings in the shape of BURPs, starting in [1993](http://www.peeron.com/inv/sets/6076-1))
  * brown (some castle accessories, such as minifig [spears](http://www.peeron.com/inv/parts/4497) or [bows with arrows](http://www.peeron.com/inv/parts/4499), at least since [1984](http://www.peeron.com/inv/sets/6073-1) ... until LEGO finally started using some brown for trees instead of approximating them with black around [1993](http://www.peeron.com/inv/sets/6552-1))
  * green (granted, this one appeared as plates in castle sets at least since [1984](http://www.peeron.com/inv/sets/6073-1), but was otherwise mostly reserved to plant parts, baseplates, and special decorative elements such as [flags](http://www.peeron.com/inv/parts/4495) ... until around 1992, when the fictional Octan gasoline brand was introduced and green started becoming a "mainstream" colour)
  
  Now, I am aware I have not listed all the parts that ever came in the respective colours; my point is that, at least in my impression, these three colours listed above were mainly used for a rather small number of accessories or other specific elements for many years, as opposed to seeing widespread use as regular plates and bricks, compared to the other aforementioned colours.
  
  **Is there any known reason in terms of business/design decisions/the material used for each of the colours for this?**
  
  **Tags:** history, colour
  > **Comments:**
  > **username_1**: The actual light grey is actually a fairly rare color. The lighter of the 2 common greys is actually medium grey, with light grey appearing only rarely (in sets like Thok and King Mathias).  
  > **username_2**: @AlexanderO'Mara: and in certain NXT components.  
  > **username_3**: This doesn’t detract from your main point, but Lego had “started using some brown for trees” already by 1989, in the palm trees of the Pirates sets, eg [Forbidden Island](http://www.peeron.com/inv/sets/6270-1).  As you say, though, this was still specialised pieces, not ordinary blocks.  
  > **username_0**: @PeterLeFanuLumsdaine: Right, "brown for trees" was an oversimplification. Pirates also brought brown ship hulls, brown ship ladders, brown oars, and some more pieces like the small wooden barrels had probably been around in Castle even a bit earlier. But, yes, this arguably makes it even more noteworthy that of all pieces, standard bricks in these colours were conspicuously absent, especially considering that Pirates *did* feature other wooden structures where wood was mimicked with black pieces (parts of pirate buildings, the crane on the imperial palace, etc.).  
  > **username_4**: I recall green flat 2x3 in the 1970s.  
  > **username_0**: @chux-ReinstateMonica: The earliest occurrence listed on [Peeron](http://www.peeron.com/inv/parts/3021?color=Green) is from 1984. Or do you mean a different part?  
  > **username_5**: Set 125 in 1974 had a [10x20 green brick](https://www.bricklink.com/v2/catalog/catalogitem.page?P=700eD&idColor=6#T=C&C=6). It was one brick tall and had connecting tubes around the bottom edge, so it's technically a brick.  
  > **username_6**: Here's an interesting, slightly relevant tidbit: maroon and to a lesser degree brown LEGOs are much more brittle than others. Try assembling an old Luke's Landspeeder set without pieces breaking on you.  
  > **username_7**: Bear in mind that the greys used in sets older than 2002 are different to modern greys.  Lego changed the colour palette in the early 00s to make the colours more child friendly and the biggest change were the greys, which were given a blue rather than brown hue.  The colour change is so dramatic that you basically can't use the two side by side in a model.  The browns were changed as well but the change was not as dramatic.  
  > **username_0**: @Stephen: I read about that, but it seems irrelevant here: The colours I list were around in special parts since the 1980s and gradually started appearing as regular bricks in tbe course of the 1990s.  
  > **username_0**: @shoover: Technically true, as you say, though "bricks" of that size are, in their possible use cases, much like "thick plates" rather than what I referred to as "regular bricks" (that are suited to build a plain wall, for example).  
  > **username_8**: I recently saw an episode of a tv show "The Toys that made us" regarding Lego. It did include some of the decisions they made (including used colors). Might be an interesting watch to get an idea why/what kind of decisions the company made.  
  > **username_9**: @O.R.Mapper Are you waiting on additional information or is there something else preventing you from accepting an answer?  
  
  ---
  
  ## 6 answers
  
  ### Answer by username_9 on 2019-12-17. Score: 49
  
  The answer I've [heard](https://bricks.stackexchange.com/a/420/3631) the [most](https://soranews24.com/2015/06/12/theres-a-reason-why-there-are-fewer-green-lego-bricks-than-any-other-color) (with a [source citing the official confirmation](https://www.zmescience.com/other/did-you-know/lego-military-toys)) is that green, brown and gray bricks were omitted from the LEGO palette because the company wanted to discourage kids from building tanks, planes, and other realistic military hardware.
  
  > **Comments:**
  > **username_0**: Wow. Never thought of this one, though when enumerating the colours as "green, brown and gray", the possible connection to camouflage becomes immediately obvious.  
  > **username_10**: There is some [further evidence to this theory](https://www.zmescience.com/other/did-you-know/lego-military-toys/).  
  > **username_9**: @T.Sar-ReinstateMonica TLG's reluctance to produce realistic, modern military equipment is clear and well known, but as far as I can see, the linked article does not mention the connection between this phenomenon and the lack of specific colours, asked by OP.  
  > **username_10**: That article doesn't connect to the color, yes, but it gives a reference for those that weren't aware of this reluctance from part of TLG. I, for one, wasn't aware of it.  
  > **username_11**: Though they had no problem including various types of guns (both in the space and pirate sets), and even working cannons (though they sadly backtracked on that one later).  There was also an extensive variety of medieval weapons in the castle sets.  So - ancient and futuristic weapons are okay, but modern ones aren't?  
  > **username_9**: @DarrelHoffman This is more like a general guideline, not a strict rule. [The official statement](https://bricks.stackexchange.com/a/294/3631) says "The basic aim is to avoid realistic weapons and military equipment that children may recognize from hot spots around the world and to refrain from showing violent or frightening situations". However, LEGO has produced sets depicting all of the above, but every time the focus is either in the model itself, like in the case of [Sopwith Camel](https://brickset.com/sets/3451-1/Sopwith-Camel) or [part 1 of 2, continued below]  
  > **username_9**: [continued] or the interaction between well-defined good and bad actors, like in some [Indiana Jones sets](https://brickset.com/sets/7625-1/River-Chase), or the militaristic personnel and equipment is an integral part of an otherwise kid-friendly franchise, like [Toy Story](https://brickset.com/sets/7595-1/Army-Men-on-Patrol) or [Lone Ranger](https://brickset.com/sets/79106-1/Cavalry-Builder-Set). Note though, that TLG has produced historical realistic fighter planes even outside of licenced themes, like [in Pharaoh's Quest](https://brickset.com/sets/7307-1/Flying-Mummy-Attack). [part 2 of 2]  
  > **username_12**: I have to say, the lack of colours *never* stopped me from producing machines of war.  You should have seen my bedroom the day after I sneakily saw Top Gun......  
  > **username_13**: Brown dogs/horses and green trees/grass/plants were quite  acceptable then, so it must have been more targetted to bricks.  
  > **username_9**: @Criggie Right, but don't forget, the plant pieces were made of polyethylene instead of ABS, which made them softer and more pliable. However, the existence of the green "baseplate" brick mentioned in [a comment by shoover](https://bricks.stackexchange.com/questions/12940/why-was-lego-reluctant-to-use-additional-colours-for-regular-bricks-in-former-ti/12944?noredirect=1#comment15275_12940) above proves that green ABS was indeed used, just not for basic bricks.  
  > **username_14**: This justification was also used in the documentary [The Toys That Made Us](https://www.netflix.com/title/80161497).  
  
  ---
  
  ### Answer by username_2 on 2019-12-17. Score: 26
  
  Early LEGO colors were inspired by the work of Mondriaan, which mainly consists of white, black, red, blue and yellow. These primary colors were considered to be most appealing to kids.
  
  [![enter image description here](https://i.sstatic.net/UKhW0.jpg)](https://i.sstatic.net/UKhW0.jpg)
  
  From the book [“Brick by Brick”](https://rads.stackoverflow.com/amzn/click/com/0307951618):
  
  > The new product was patented in 1958 and within a few years bright
  > yellow, red and blue Lego bricks, colours inspired by the paintings of
  > the Dutch Modernist painter Piet Mondrian, were scattered across the
  > floors of millions of homes.
  
  > **Comments:**
  > **username_0**: Interesting, but is this just speculation, or do you have any references to back this up?  
  > **username_2**: From the book “Brick by Brick”:  The new product was patented in 1958 and within a few years bright yellow, red and blue Lego bricks, colours inspired by the paintings of the Dutch Modernist painter Piet Mondrian, were scattered across the floors of millions of homes.  
  > **username_2**: @Keeta-reinstateMonica Done!  
  > **username_20**: Does *Brick by Brick* indicate in any way **their** source for this? The use of primary colors in kids’ products is pretty wide-spread, and I have doubts that Piet was the direct inspiration for that in a variety of settings. Something from LEGO themselves would seem necessary to cement this claim.  
  > **username_21**: This justification was also used in the documentary [The Toys That Made Us](https://www.netflix.com/title/80161497).  
  > **username_22**: I did not realize there was a link between LEGOs and The Partridge Family.  Wow.  
  
  ---
  
  ### Answer by username_15 on 2019-12-19. Score: 16
  
  I have a background in precision injection moulding, although not to the extremely tight tolerances of Lego. Here's why a manufacturer would try to reduce the number of colours they used, particularly in the old days.
  
  Most resin (the raw material) nowadays comes pre-coloured, especially for a large customer like Lego. That wasn't the case fifty or sixty years ago: we used to get white resin and colour it with powdered pigment. This operation would have to be repeated for each batch of each colour, a batch being (in the old days) a cement mixer's worth of resin. Between colours you would need to clean the mixer out thoroughly, because a small amount of the wrong pigment could contaminate many pieces. The contamination would be hard to see: try examining 1,000 pieces for a small swirl of the wrong colour!
  
  If the colour of a moulded piece was off we would have to re-grind it, add more pigment / plain resin and re-mould it. We couldn't do that for pieces of different colours, or for badly contaminated pieces. We had the advantage of manufacturing some products in black that would hide most discolourations, so we would reserve contaminated material for those.
  
  Moulding machines used to have a hopper above the machine, and the coloured resin would literally be carried up a ladder and poured inside. To switch between colours we would generally run the hopper until it was almost empty, possibly add some plain or disposable reground material to "purge" it, and then add the new material. A certain amount of pieces would necessarily be contaminated by the old colour, which meant that changing colours for small batches could be quite wasteful. Nowadays we have vacuum feeders instead of large hoppers. We still have the problem of colour contamination, but this has been reduced by better mould design.
  
  Speaking of moulds, older moulds used to convey the plastic down a channel to the moulds for the individual pieces. When the mould emptied the channels, called sprues, would separate or be sepaarated from the puieces and reground. There would invariably be a certain amount of this material left at the end of a job, and it could be a pain keeping track of it for next time.
  
  When you add these costs in time/quality together it's easy to see that (keeping the total number of pieces constant) adding extra colours rapidly increases your overheads. It isn't just the fixed cost of changeover and storage, but the potential for things going wrong. I think this would have given Lego a good reason to reduce the number of colours they used, particularly when the firm was smaller and technology wasn't as advanced.
  
  > **Comments:**
  > **username_16**: Thanks for this detailed answer, and welcome to Bricks.SE!  
  > **username_17**: LEGO used to produce bricks from pre-coloured raw material, however they've switched base+color pellets nowadays. I'm not entirely sure why (probably due to cost saving), but this introduced problems with color consistency, which is still hasn't been resolved until today.  
  
  ---
  
  ### Answer by username_18 on 2019-12-17. Score: 15
  
  A practical engineering concern could be a reason to limit the colours used for molding in ABS plastic.
  
  The colourant added to the base plastic can affect the physical properties of the molded part. Depending on how tight the dimensional tolerances are for the finished part a separate mold may be required for each colour.
  
  Perhaps the Lego group process engineers have enough controls in the automated molding process now to tweak the mold setups to compensate for the variations induced by the colourants.
  
  > **Comments:**
  > **username_0**: You may be on to something there, given that the early swords may indeed be somewhat softer, as were various of the earlier green pieces ([old trees](http://www.peeron.com/inv/parts/3470) and [whips](http://www.peeron.com/inv/parts/2488), for example - but obviously not the plates), pointing to differences in the material. Do you have any references to back this up?  
  > **username_19**: @O.R.Mapper I'm fairly sure those pieces were deliberately made in softer material to be slightly movable, to avoid breaking. They're generally things containing longer or thinner pieces that would easily be subjected to accidental damaging force. I doubt this is related to the colour.  
  > **username_0**: @Nyerguds: Certainly. In the case of whips, for instance, they are intentionally softer as they are *meant* to be bent for some sets. I rather thought of it the other way round: Maybe certain colours were somehow easier or cheaper to manufacture with soft materials, so they were used for parts that were always manufactured from softer material in the regular colours, as well.  
  
  ---
  
  ### Answer by username_23 on 2019-12-17. Score: 4
  
  Manufacturing logistics play a part in this decision. If you have to maintain six different dyes or pellet hopper combinations in the injection molding pipeline in your factory, that is a different story in terms of cost than maintaining sixteen or thirty hopper combinations or dye vats. If the pellets are pre-dyed (as I believe was the case), sourcing these will depend on the logistics of and the options made available by the supplier.
  
  > **Comments:**
  > **username_9**: It's [known](https://bricks.stackexchange.com/q/8543/3631) that LEGO has had problems sourcing red and yellow colours that did not contain cadmium, but no such problems have been known about green, brown or grey.  
  > **username_9**: Also, the existence of the green "baseplate" brick mentioned in [a comment by shoover above](https://bricks.stackexchange.com/questions/12940/why-was-lego-reluctant-to-use-additional-colours-for-regular-bricks-in-former-ti/12944?noredirect=1#comment15275_12940) proves that green ABS was indeed used, just not for basic bricks.  
  
  ---
  
  ### Answer by username_24 on 2019-12-18. Score: 3
  
  Most bricks in sets are picked from large bins of a given colour/shape when making up a set, and used in many different sets. Hence there is a cost advantage to limiting the number of colours and hence the number of different brick.
  
  > **Comments:**
  > **username_0**: So, why did (the importance of?) that cost advantage gradually change or vanish starting toward the end of the 1980s?  
  > **username_24**: @O.R.Mapper I **expect** automatic systems for picking bricks from many bins,  and increased production levels.   Along with them wishing to create more realistic models.  
  
  ---
  
  