### 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)

if (index->type == Node::NODE_TYPE_CONSTANT) {
						uint32_t index_constant = static_cast<ConstantNode *>(index)->values[0].uint;
						if (index_constant >= (uint32_t)expr->get_array_size()) {
							_set_error(vformat(RTR("Index [%d] out of range [%d..%d]."), index_constant, 0, expr->get_array_size() - 1));
							return nullptr;
						}
					}
					member_type = expr->get_datatype();
					if (member_type == TYPE_STRUCT) {
						member_struct_name = expr->get_datatype_name();
					}
				} else {
					switch (expr->get_datatype()) {
						case TYPE_BVEC2:
						case TYPE_VEC2:
						case TYPE_IVEC2:
						case TYPE_UVEC2:
						case TYPE_MAT2:
							if (index->type == Node::NODE_TYPE_CONSTANT) {
								uint32_t index_constant = static_cast<ConstantNode *>(index)->values[0].uint;
								if (index_constant >= 2) {
									_set_error(vformat(RTR("Index [%d] out of range [%d..%d]."), index_constant, 0, 1));
									return nullptr;
								}
							}
							switch (expr->get_datatype()) {
								case TYPE_BVEC2:
									member_type = TYPE_BOOL;
									break;
								case TYPE_VEC2: