When I'm board, I like to make themes for wikis that doesn't have them. You can see a preview here http://maistesting.wikia.com/wiki/Special:WikiActivity
Here is the favicon. File:Newfavicon.ico
Here is the wallpaper. The background has to be white (#ffffff) and the buttons, links, and header has to be #760300 AND the second colour has to be white (#ffffff) and not transparent.