If you are common with hex codes of colours (example: white is #FFFFFF) you can do this manualy, but be careful.
You can also set it to use a different colour every time the page loads...there are a few articles on here how to do so. One example is the adsense block at the top of the forum.
yip you can change the HEX code for the colours just watch you don't alter the code outwidth Googles TOC.