### 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)

break;
								case TYPE_VEC3:
									member_type = TYPE_FLOAT;
									break;
								case TYPE_IVEC3:
									member_type = TYPE_INT;
									break;
								case TYPE_UVEC3:
									member_type = TYPE_UINT;
									break;
								case TYPE_MAT3:
									member_type = TYPE_VEC3;
									break;
								default:
									break;
							}
							break;
						case TYPE_BVEC4:
						case TYPE_VEC4:
						case TYPE_IVEC4:
						case TYPE_UVEC4:
						case TYPE_MAT4:
							if (index->type == Node::NODE_TYPE_CONSTANT) {
								uint32_t index_constant = static_cast<ConstantNode *>(index)->values[0].uint;
								if (index_constant >= 4) {
									_set_error(vformat(RTR("Index [%d] out of range [%d..%d]."), index_constant, 0, 3));
									return nullptr;
								}
							}
							switch (expr->get_datatype()) {