I don't know if this is a css problem or a module problem.

I just installed the forum module and the category titles are dark text on a dark background--nearly invisible. I'd like to change the text to white.

Anybody know where I do that?

I'm using the default theme.

I was able to solve this problem by adding three lines to the css file.

After these lines:
a {color: #666666; text-decoration: none; font-weight: bold; background-color: transparent;}
a:hover {color: #ff6600;}

Add these lines:
table.outer th a:link {color: #ffffff;}
table.outer th a:hover {color: #ff6600;}
table.outer th a:visited {color: #aaaaaa;}

It took a long time but I was able to learn something about css, classes and id's in the process.