I would like to suggest to add an option to disable search term highlighting.
Rationale: Most of the time I'm not really searching for a particular term but rather for a topic. In those cases, I feel that the (sometimes extensive) highlighting clutters the page display. If I'm really searching for a term, I can easily use the browser's find function. Getting rid of the highlighting (by modifying the URL) is much more difficult.
As far as I can tell, disabling search term highlighting would mean changing the search result page to create links *not* containing an "&s=..." extension.
I know about the workaround by adapting the color handling in conf/userstyle.css, see http://forum.dokuwiki.org/post/16778
Thanks for reading, Malte