Take a look at the final result, shown below, of switching the selected theme to UI Lightness and UI Darkness, which are the unmodified jQuery UI Themes added to ScrewTurn Wiki’s /Themes folder.
The layout could use a little tweaking here and there and I haven’t updated all the pages to use jQuery UI Themes, but the technique works. We can now use ThemeRoller to build custom ScrewTurn Wiki Themes. If you use Firefox, you can use the ThemeRoller Firefox Bookmarklet to design custom themes right on your own wiki! Once you’re satisfied with the results, just download your new custom theme and deploy it to your /Themes directory.