Last week I had 2000 impressions, 0;3 percent whilst ads were blended. This week, 2200 impressions, 4.3 percent whilst ads were NOT BLENDED. The key is to experiment and test.
Blending never worked for me. I always prefer to keep my ads "distinctly visible". IMO. the best stratergy is to make a site in 3-4 similar colours and use totally contrasting colours for the ad titles.
blending depents on your site. if you have an article site, it's better to have a good blending site but for the game sites, i believe less blending is better