It's called optimization.
Once you have a blog up and running, and you've got AdSense on it, you'll probably want to get away from the skyscraper and leaderboard ad configurations. And you'll also want to configure the color patterns of your advertisements so that the ad link matches the other links on your page, the backround matches your backround, and the text matches your text.
You want your advertisements to appear as part of your page, rather than ads that scream, "Hey look at me, I'm an advertisement, IGNORE ME!" When ads stand out, your readers may develop what it known as "ad blindness," where they will focus on your content and completely ignore the advertising.
But you want to provide content as well as useful and relevant advertising as a service to your readers.
You can optimize your colors by taking the following steps.
1. Identify your blog's colors. You need to be able to identify the backround and link colors by a six digit alphanumeric code (letters and numbers) so that you can then customize your Adsense ads to use those same color identification numbers.
Go to your blog's template settings, and click on fonts and colors. From here, find the colors you want to match from your blog, click on them, and write down the color codes.
2. Match your Adsense colors to your blog. Now go into your Adsense homepage, click Adsense Setup, and select Adsense for Content. Next, select "Ad unit" and click "continue."
Now you should see a color pallet next to boxes with the six digit alphanumeric codes. Plug in the codes you've written down, and watch the new colors pop up. Make the border and backround color the same.
The more your content and advertising looks like a coherent unit, the more pleasing your website will be to the eye of your reader, and the more likely they are to make use of your advertising!