I'm a fan of the Monokai colour scheme for my source code editing and thus set up it whenever I can in the IDEs I use.

For JetBrains' IntelliJ IDEA I use Long Cao's Monokai colour scheme. Grab the XML file and drop it, on Windows, in your %HOMEPATH%.IntelliJIdea11configcolors directory. Restart IDEA and the Monokai colour scheme ought to be present in the dropdown box under File » Settings » Editor » Colors & Fonts » Scheme Name.