Background Color

I want to change to background color #FFFFFF to another color, but I can't find this right place to do it. Does anyone know how to do this?

Invisible Text

There is a great deal of text that does not appear. I know it's there because when I highlight it, it shows up. Some text does appear, but examples of where it doesn't, are "Welcome, 'name'" and in the body of the post. I'm guessing the text is white and the background is white, but how do I fix this?

using Joomla 1.5.2
JooBB 5.8

Thanks, and great work on this extension!