As a rule, if your "underline" is not the same color as your text [and the 'color:' is not overridden inline] it is not coming from "text-decoration:" It has to be "border-bottom:"
Don't forget to take the border off your pseudo classes too!
a, a:link, a:visited, a:active, a:hover {border:0!important;}
This snippet assumes its on an anchor, change to it's wrapper accordingly... and use specificity instead of "!important" after you track down the root cause.