You can customize the appearance of components in your applications by modifying one or both of the following elements:
Styles
Each component has a set of styles that you can set to specify what values Flash
uses to render the component's appearance. Styles generally specify skins and
icons to use for a component in its different states and also what text
formatting and padding values to use.
Skins
A skin consists of the collection of symbols that make up the component's
graphical appearance in a given state. While a style specifies what skin to use,
a skin is a graphical element that Flash uses to draw the component. Skinning
is the process of changing a component's appearance by modifying or replacing
its graphics.
Note: The default appearance of ActionScript 3.0 components could be considered a theme (Aeon Halo), but these skins are built into the components. The ActionScript 3.0 components do not support the external theme files that ActionScript 2.0 components did.