### 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 (tk.type != TK_PARENTHESIS_CLOSE) {
										_set_expected_error(")");
										return ERR_PARSE_ERROR;
									}
									new_hint = ShaderNode::Uniform::HINT_RANGE;
								} break;
								case TK_HINT_INSTANCE_INDEX: {
									if (custom_instance_index != -1) {
										_set_error(vformat(RTR("Can only specify '%s' once."), "instance_index"));
										return ERR_PARSE_ERROR;
									}
									tk = _get_token();
									if (tk.type != TK_PARENTHESIS_OPEN) {
										_set_expected_after_error("(", "instance_index");
										return ERR_PARSE_ERROR;
									}
									tk = _get_token();
									if (tk.type == TK_OP_SUB) {
										_set_error(RTR("The instance index can't be negative."));
										return ERR_PARSE_ERROR;
									}
									if (!tk.is_integer_constant()) {
										_set_error(RTR("Expected an integer constant."));
										return ERR_PARSE_ERROR;
									}
									custom_instance_index = tk.constant;
									current_uniform_instance_index_defined = true;
									if (custom_instance_index >= MAX_INSTANCE_UNIFORM_INDICES) {