### 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 (p_node->type == Node::NODE_TYPE_OPERATOR) {
		OperatorNode *op = static_cast<OperatorNode *>(p_node);
		if (op->op == OP_INDEX) {
			return _validate_assign(op->arguments[0], p_function_info, r_message);
		} else if (_is_operator_assign(op->op)) {
			
			return _validate_assign(op->arguments[1], p_function_info, r_message);
		} else if (op->op == OP_CALL) {
			if (r_message) {
				*r_message = RTR("Assignment to function.");
			}
			return false;
		}
	} else if (p_node->type == Node::NODE_TYPE_MEMBER) {
		MemberNode *member = static_cast<MemberNode *>(p_node);
		if (member->has_swizzling_duplicates) {
			if (r_message) {
				*r_message = RTR("Swizzling assignment contains duplicates.");
			}
			return false;
		}
		return _validate_assign(member->owner, p_function_info, r_message);
	} else if (p_node->type == Node::NODE_TYPE_VARIABLE) {
		VariableNode *var = static_cast<VariableNode *>(p_node);
		if (shader->uniforms.has(var->name)) {