The PrimeFaces theme gallery already provides more than 30 built-in themes if you want to choose the right theme for your applications. The theme gallery also includes other component library-specific themes, which are useful in migration.
For example, if you are using Apache Trinidad or JBOSS RichFaces, then the PrimeFaces theme gallery already contains Trinidad's Casablanca and RichFaces' BlueSky theme so that you can make PrimeFaces look like the Trinidad or RichFaces components during migration.
However, you will encounter many situations where none of the predefined PrimeFaces themes exactly fit your needs. In these cases, you can customize your own theme. We shouldn't start creating the theme from scratch. But first, you have to select a theme that is close to what you need and then tweak the theme as per your requirements using the ThemeRoller tool (Fore more information about ThemeRoller, visit http://jqueryui.com/themeroller/).
We have already...