A method, computer program product, and data processing system for modifying attributes of GUI components without invasive code modification are disclosed. In a preferred embodiment, a set of attributes for GUI components is loaded into memory from persistent storage, such as a file. A root container component forming the root of a hierarchy of components defined by a containment relation is identified and passed as a parameter to a routine that traverses the hierarchy so as to visit each GUI component. As each GUI component is visited, if one or more attributes from the aforementioned set of attributes are found to be applicable to the visited GUI component, the GUI component's attributes are modified to comport with the set of attributes.