I knew it could be done, but it never occurred to me to mess with it. But now I'm just sitting here, stoned, hitting refresh, because I couldn't figure it out and now I want to know...
The little color box to the right of "Chill Out Zone" along the white forum user-bar near the top of the page. Click it for a rainbow at your fingertips.
I went with a nice deep green. I liked the colors of the old forum format and this is as close as it gets I'd post a screenshot but its exactly the same color as OP's
See im not so sure I could use the vibrant purple, the brown is alright but I looked around at colors for a while and this green kept fresh in my mind
i just use the default colour, but the white is a bit bright and i cant figure out how to change it, i downloaded stylebot but i cant figure it out