you have 2 choices
1-add to your css, tcat or thead whichever it is
this way all non links will also be white in there
2-Navigate to the page, e.g.
http://www.site.com/forums/vbtrade.php to make sure it's the correct link, then you copy the address from your browser and go back to edit the module. In the Module Shell Template Options, if you are using it, then you put in the link in module link.
Go with the css solution also as sometimes you will not have link. But still link those you can.