Hi,
More of an answer than a question, but thought I'd share this as I've just managed to workout using the Firefox add-on, Firebug, (Original source here) - how to highlight the results search term on a google custom search, which had been bugging me for a while now.
Simply add this to your stylesheet, et voila - .gsc-results .gs-snippet b { background-color:#ff3100; padding:0 3px; color:#FFF; }
Hope this helps someone as I couldn't find anything on it.