I was able to create my own theme with themeroller and use it in primefaces as explained in the manual.
Then I tried this: http://jqueryui.com/themeroller/developertool/ Should this work with primefaces? It doesn't load any theme settings from the page or change them. I am using Firefox 4.
Edit - Is this maybe a problem using it with Firefox 4. I can't get it to work anywhere.