Admin Forum:Changing admin username color?

I have seen in many wikis that admins' usernames have a special color. I found a thread about it, in this wiki, but it's inactive and it doesn't say, where to do it. So, will someone tell me, how to do it and where to do it? 12:33, August 7, 2012 (UTC)
 * In your wiki's MediaWiki:Common.css put a[href="/wiki/User:USERNAME"] { color:COLOUR NAME !important; font-weight: bold !important; }

-- http://i151.photobucket.com/albums/s145/urbancowgurl777/UltimateSupreme2212-3.png  (Talk to me) 12:51, August 7, 2012 (UTC)