Can I set the background to another color?

I'm using a kinda dark theme with all my editors (like Xcode and TextMate) and get used to it. It's a bit like a shock when I run a git diff from my also-dark Terminal and the Changes.app appear all in bright, shiny white. Is there a hidden pref to change the background color to black?

Perhaps for Changes 2 it's a good idea to integrate the TextMate language bundles to get syntax highlighting? I would love to see syntax highlighting in Changes.