I just do an experiment with my well known blog. that i changed the theme and color of ads and i really got gud results. not inreased my clicks but earnings increased slightly.. it increased upto 50% per click... now i m earning double of that amount which i was earning before.. what do you think about that. the blog is http://urdoogle.com
Ya color and themes of the website or blogs highly matters. It have been seen that visitors can't stay longer to the website having dark background colors because after 5-10 min. of read it start hurting their eyes.