I realize this is off topic, but there isn't really an appropriate place to discuss. I also felt that computer users may be more interested.
As far as I can tell, there is no way to control the background color on the AVS forums. Often it can be very difficult to read.
Even if you aren't interested in TiVo, check out the TiVo forum hosted here. It seems to be the only board with a white background. I find it much easier to read.