Color search box

Thank you for making such a wonderful theme. it's the best I've encountered so far and I'm not gonna look any further ;) I do have a question. We use Kathmandu Pro and we're using the dark version, but now the search box is a little 'lost' in the black background. So I was hoping for a way to change the color (or should I say background color?) of the search box. You can take a look here, the search box is beneath the menu at the top of the page: http://www.egyptologie.nl/Boekenverkoop/ The text says 'zoeken' which is Dutch for 'search'.