What are the levels of skin definition?
4.4.2. Using Skinnability RichFaces skinnability is designed for use alongside: skin parameters defined in the RichFaces framework, predefined CSS classes for components, and user style classes. A component's color scheme can be applied to its elements using any of three style classes: A default style class inserted into the framework This contains stle parameters that are linked to some constants from a skin. It is defined for every component and specifies a default level of representation. You can modify an application interface by changing the values of the skin parameters. A style class of skin extension This class name is defined for every component element, and inserted into the framework to let you define a class with the same name in your CSS files. This lets you easily extend the appearance of all components that use this class. User style class You can use one of the styleClass parameters to define your own class for component elements. As a result, the appearance of one particular component is changed according to a CSS style parameter specified in the class.