Basically themes are only CSS stylesheets that controls the colors of the syntax highlighthing. I'll be adding new ones every now and then. In the meantime, here is an example theme, so if anyone wants to make their own theme and suggest it via the form below, I will add them. Just copy this example and change the colors to your liking.
It's very easy to suggest a theme; just paste your theme's CSS as a new snippet on this very site and paste your snippet ID right here. (The snippet id looks like this: htsnip4894bb9cd26e3)