I actually just did this the other day. You have to enter your stylesheet into both the main page and in the message board. The following Stylesheet will change everything you need to change. There are 5 more things you can add and I'll list them at the very bottom of this page. Just play around with all the colors till you've got what you want.

The first two in the stylesheet above change the colors of the text, and the last changes the BG color.

.community { color: #ffffff; }
.community a:link{ color: #996633; }
.community a:visited{ color: #cc6633; }
.community a:active{ color: #ffcc33; }
.community a:hover{ color: #990033; }