usa gli stili alternativi
ad esempio :


<link rel="stylesheet" type="text/css" href="miostile.css" title="default" />
<link rel="alternate stylesheet" type="text/css" href="miostile1.css" title="uno" />
<link rel="alternate stylesheet" type="text/css" href="miostile2.css" title="due" />
<link rel="alternate stylesheet" type="text/css" href="miostile3.css" title="tre" />
<link rel="alternate stylesheet" type="text/css" href="miostile4.css" title="quattro" />
<script Language="JavaScript">
function setActiveStyleSheet(title) {
var i, a, main;
for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title")) {
a.disabled = true;
if(a.getAttribute("title") == title) a.disabled = false;
}
}
}
</script>


e poi per richiamarne uno:

onMouseOver="setActiveStyleSheet('tre')