Relationship between theme and adds

Hello friends!

I am thinking in change my blog’s template, but I don’t get to decide for any template, because I always be afraid due to possible problemas regarding afiliate programs that I will use (Adsense and another afiliate programs and systems).

The theme I pretend to choose has a top image with ± 230 pixels of height, and the backfround of the post area is “gray”, instead of “white”. His color is #EDEDED. It is a 3 columns theme.

I am a beginner yet, and would like to know, please, if is there some problem in the usage of a theme as the above mentioned.

I am afraid due to the fact of the top image has 230 pixels of height, and so, I possibly will lost util area, that could be used to show advertising

I am also afraid due to the fact that the post area is not white.

Do you think that the above factors can interfere with the SEO and displaying of advertising, and/or prejudice the positioning of my blog in search engines, as Google, for example?

And regarding the post area that is not white: can this prejudice my blog, or my SEO, or my positioning on search engines?

I would be very grateful if someone could help me. 🙂

Best Regards.