SetUI() is in most extensions of JComponent. You can call getUI() to get the component's UI delegate, and setUI() to set it. The javax.swing.plaf package contains abstract classes which define the basic behavior of UI Delegates. Components delegate the implementation of their UI to UI Delegates. This system is how you can switch between Metal, Windows and Motif Look & Feels. If you are really bored with your Fly By Night project you could start subclassing the abstract UI Delagate classes in javax.swing.plaf and write your own L&F.