Changing the popUpMenu colors

Hello everyone. I have created a popUpMenu. It works fine. It's simple. Case, Break. Easy. What I'd like to know, if anyone can shed some light on, is it possible to change some of the colors. Would there be a javascript to do the trick? Like the text or the background of it or the highlight bar when I scroll up/down in it? At the present, it only has black for the text, blue for the highlight bar and white for the background. I would like to try to change it, just to see what the popUpMenu would look like. Any feedback would be welcomed. Thanks folks.