cmyk-syntax
A syntax theme using (something close to) three of the four printing colours (k is covered by the background).
Because I find syntax highlighting more useful when reading code than writing it this theme only highlights a few elements, such as class and function definitions, return statements and comments.
The theme works for python, javascript and HTML. Mileage will vary in other languages - if your favourite is missing raise an issue, or make the changes and send me a pull request.