Strange. I re-wrote it using less characters (438) than any browser needs...yet Firefox still behaves the same way. If you watch closely, everything changes...then it loads the new page content.
Code:javascript:es=document.getElementsByTagName("*");for(i=0;i<es.length;i++){e=es[i];c=e.className;t=e.tagName.toLowerCase();if(c=="panel"||c=="panelsurround"){e.style.background="#eeeeee";}if(c=="tborder"||c=="tfoot"||c=="tcat"||c=="thead"||c=="vbmenu_control"){e.style.background="#425a89";}if(c=="alt1"){e.style.background="#f5f5ff";}if(c=="alt2"){e.style.background="#e1e4f2";}if(t=="body"||t=="textarea"){e.style.background="#ffffff";}}