I've done it quickly like this :
... placed this in the Style header :
Code:
.quoteBox{
border : 1px solid #000000;
background-color : #9999bb;
font-family : arial,helvetica,sans-serif;
font-size : 12px;
color : #000000;
}
... then in your AdminCP, edit your Custom vB Codes, and find the QUOTE entry, edit it and replace with somthing like this :
Code:
<table cellpadding=4 cellspacing=0 width=98% class="quoteBox">
<td align=left valign=center><smallfont><b><u>quote:</u></b></smallfont></td>
<tr><td align=left valign=top>{param}</td></tr>
</table><p>