### Godot version

v4.1.dev.custom_build.a7276f1ce

### System information

Win10, AMD 2600, GeForce GTX 1060, Vulkan API 1.3.205

### Issue description

I can't get correct color data from an array of source_color type.
The color data is saved as **Color** in the file:
`shader_parameter/palette = [Color (1, 0, 0, 1), Color (0, 1, 0, 1), Color (0, 0, 1, 1)]`
Shouldn't it be saved as PackedColorArray?


### Steps to reproduce

1.Declare an array of source_color type.
2.Set colors.

### Minimal reproduction project

[shadertest.zip](https://github.com/godotengine/godot/files/11246504/shadertest.zip)

expression_block->use_comma_between_statements = true;
			cf->blocks.push_back(expression_block);
			err = _parse_block(expression_block, p_function_info, true, false, false);
			if (err != OK) {
				return err;
			}
			BlockNode *block = alloc_node<BlockNode>();
			block->parent_block = init_block;
			cf->blocks.push_back(block);
			p_block->statements.push_back(cf);
#ifdef DEBUG_ENABLED
			keyword_completion_context = CF_BLOCK;
#endif 
			err = _parse_block(block, p_function_info, true, true, true);
			if (err != OK) {
				return err;
			}
		} else if (tk.type == TK_CF_RETURN) {
			
			BlockNode *b = p_block;
			while (b && !b->parent_function) {
				b = b->parent_block;
			}
			if (!b) {
				_set_parsing_error();
				return ERR_BUG;
			}
			if (b->parent_function && p_function_info.main_function) {
				_set_error(vformat(RTR("Using '%s' in the '%s' processor function is incorrect."), "return", b->parent_function->name));
				return ERR_PARSE_ERROR;