#userinfo .member_username is the CSS variable. I know it works because it does mark up the profile for those usergroups without any color. Can't really remember everything I've tried. Changing from font color to span style, !important and the like. When I inspect the element, basically it shows the element.style color overriding the #userinfo .member_username color I've set in additional.css.
Link:
http://www.sycamorepride.com/member.php?1-Jason-Svoboda