### 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)

}
						mn->index_expression = index_expression;
					} else {
						_set_tkpos(prev_pos);
					}
				}
				expr = mn;
#ifdef DEBUG_ENABLED
				keyword_completion_context = prev_keyword_completion_context;
#endif
				
				
				
				/*} else if (tk.type==TK_BRACKET_OPEN) {
				
				//subindexing has priority over any operator
				
	*/
			} else if (tk.type == TK_BRACKET_OPEN) {
				Node *index = _parse_and_reduce_expression(p_block, p_function_info);
				if (!index) {
					return nullptr;
				}
				if (index->get_array_size() != 0 || (index->get_datatype() != TYPE_INT && index->get_datatype() != TYPE_UINT)) {
					_set_error(RTR("Only integer expressions are allowed for indexing."));
					return nullptr;
				}
				DataType member_type = TYPE_VOID;
				String member_struct_name;
				if (expr->get_array_size() > 0) {