You can change all that stuff in the settings; if you come up with a set you think looks better, I'd love to investigate.
As for font, what browser/OS are you on? It is using Segoe UI as the main font, but sadly this isn't installed on all computers. The backup is Arial, which I agree could be better.
I quickly did this with Stylebot for Chromium: http://min.us/iErKG.png :) I'm sure other readers of this thread can come up with something much nicer. Perhaps you should offer a challenge for who can make the best one.
But I already prefer this css to the original. I think I'll keep it.
As for font, what browser/OS are you on? It is using Segoe UI as the main font, but sadly this isn't installed on all computers. The backup is Arial, which I agree could be better.