There are 3 color palettes that you can use for your adsense ads. 1. Blend 2. Complement 3. Contrast Please follow this link if in case you don't understand these palettes https://www.google.com/adsense/support/bin/answer.py?hl=en&answer=17957 Participate in the pool and explain why do you prefer a certain color palette over another? Include your split testing/trial and error experiences as well if possible.
I think blending is best and make the text link the same color as the links on your site so the ads don't really look like advertising.
I think contrast is not bad either, Might look uglier but the ads are highlighted, so getting some visitor attention. It's like doing something controversial to get media attention (Celebs do that you ).