Your code doesn't have to look so sour. I've collected a list of Xcode themes and fonts that you can install. Read my blog post which also contains a collection of fonts.
by Enormego
The only light theme that made the list.
Inspired by the famous Railscast TextMate theme.
My absolute favorite!
- Copy the theme(s) to the Xcode's
FontAndColorThemesfolder (~/Library/Developer/Xcode/UserData/FontAndColorThemes/). - Restart Xcode.
- Enjoy.