Boy, that Jen girl (woman) from Jensense is every where. Today she has a post on the YPN blog about color matching ads.
Jennifer outlines four techniques you can use to determine the best color scheme for your site:
1. The blended technique (using same colors for ads and site)
2. The matching technique (ad colors are from the same palette as the site colors, but not necessarily for the same elements, ie – page background color for ad text color)
3. The complimentary technique (ad colors that complement your site)
4. The contrasting technique (using ad colors that look ugly on your site, best to avoid this scheme if you want repeat visitors)
As Jennifer mentioned, its best to setup categories (channels for adsense people) and test your color schemes to see which works best for your site. With the right color scheme, your revenue can increase dramatically.