Is it better for the ads on a page to stand out, or to blend in with the rest of the content? (which generates a higher CTR?)
The ads that generate the best CTR are the ads that are most relevant to your topic. I find the highest CTR on sites where people spend time actually reading what I'm writing. By gaining their interest in my article, they're more likely to click an ad IF it is relevant to my article. Placement and color does mean a lot for those trying to "trick a click" as I call it. Lately I've played more with actually putting ads in sidebars under the Sponsored Links headers and even bringing them out of the blending routine so my readers don't think I am tricking them. My CTR went up and so did my eCPM.
I dont think it's a simple Yes/No answer. Test which color schemes work best for your site and visitors.
The thing is... I can't test different schemes because, I never really get any clickthrus anyway. LOL. But maybe testing different colorschemes and placements will generate more clickthrus.
If your not getting any clickthroughs at all, I would concentrate on working on creating more targetted content, to give the adsense bots a better chance of knowing what the theme of the article is all about. If visitors arent clicking, its because the ads being served are of no relevance to the page they landed on.
Alot depends on the mindset your viewers have when they get to your page. Are they in "hunt" mode? Looking to buy something? or are they just there to visit a community they've joined? Websites such as forums/community sites generally have better luck with attention getters, whereas info/content/article sites usually have better success with the blended color schemes. It's all about the testing! Use your custom channels wisely.. you can set them up to know exactly what ad sections are getting clicked, just have to figure out why.
It's quite surprising that when I moved the ads to the very top of my main page, my CTR dropped. So now I'm moving them back to the middle of the pages.