I've been looking around the forums trying to figure out how to fix the dropdown search for Categories on Bender, (I use Bender I do not know if this will work on any other theme).
After piecing together different suggestions from various members, this is what I've been able to do.
***NOTE*** This does appear differently in various browsers. The categories will be bold in Firefox, but in Chrome and IE the categories will be a different color, (that's good enough for me unless anybody can fix that).
Open /oc-content/themes/Bender/css/main.css
At the very end of the css, add this. You'll have to edit the child #number values to match your own categories.
#sCategory { background-color: #ff0; }
option:nth-child(2), option:nth-child(4), option:nth-child(10), option:nth-child(16), option:nth-child(21), option:nth-child(26), option:nth-child(32), option:nth-child(37), option:nth-child(43), option:nth-child(62) {
font-size: 14px;
color: blue;
font-size: 16px;
font-weight: bold;
}
The first image is Firefox result, the second image is IE and Chrome result