GNOME Panels

I recently installed RedHat 8.0, and I like the improvements to the interface since the last version I tried (probably 6.0). I know that a lot of that has to do with GNOME 2.0. Here's my question: how do I change the color of the "GNOME Panels"?

Also, are there any good places to find themes around here? And if I do find a theme, what kind of theme(s) should I look for? The only site I did manage to find had so many different categories of themes and icons that it was a little overwhelming.

Thanks!