Google have launched the official Google Chrome themes channel allowing for one click customisation of the super-fast open source browser.
Google Chrome (and by extension Chromium) both support themes on Linux. (You may need to add ”-enable-extensions to your run command.)
Browser the gallery over at: http://tools.google.com/chrome/intl/en/themes/index.html
In fact Chrome is largely stable on Linux, and even supports Flash playback. Font rendering has been sorted, as have various other subtle but annoying bugs such as not being able to drag tabs out. I even use it as my default browser in Ubuntu!