### 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)

bool struct_dt = false;
					DataPrecision precision = PRECISION_DEFAULT;
					if (tk.type == TK_STRUCT) {
						_set_error(RTR("Nested structs are not allowed."));
						return ERR_PARSE_ERROR;
					}
					if (is_token_precision(tk.type)) {
						precision = get_token_precision(tk.type);
						tk = _get_token();
#ifdef DEBUG_ENABLED
						keyword_completion_context ^= CF_PRECISION_MODIFIER;
#endif 
					}
					if (shader->structs.has(tk.text)) {
						struct_name = tk.text;
#ifdef DEBUG_ENABLED
						if (check_warnings && HAS_WARNING(ShaderWarning::UNUSED_STRUCT_FLAG) && used_structs.has(struct_name)) {
							used_structs[struct_name].used = true;
						}
#endif 
						struct_dt = true;
					}
					if (!is_token_datatype(tk.type) && !struct_dt) {
						_set_error(RTR("Expected data type."));
						return ERR_PARSE_ERROR;
					} else {
						type = struct_dt ? TYPE_STRUCT : get_token_datatype(tk.type);
						if (precision != PRECISION_DEFAULT && _validate_precision(type, precision) != OK) {
							return ERR_PARSE_ERROR;
						}