WOO HOO FOUND ONE. Sorry to bore those of you who are genius but maybe this will help other bewildered...
customer/main/product_t.tpl
added - <td width="{$width}%" class="PListCell"
onmouseover="style.backgroundColor='#84DFC1';"
onmouseout="style.backgroundColor='#84C1DF'">
http://www.basictips.com/table-cell-background-colors-change-mouseover-css.shtml