User blog comment:Sannse/Important Updates on Wikia’s New Look/@comment-1852525-20100928205047/@comment-8-20100929181527

You will need to move some CSS from common.css to wikia.css if you have anything custom in there. And a few wikis with content area code in monaco.css will need to move that too. But most wikis don't have anything in there that needs moving, so can just use the Theme Designer to change their color scheme to whatever they want