I have seen some sites where adsense publishes are using eye catching adsense background images. Even I saw adsense team members were ensuring that it is allowed if used safely. plz check these links and ensure me that if i use it safely and show ads perfectly then will it be allowed? http://andybeard.eu/282/adsense-guidelines-contextual-ads-adsense-backgrounds.html http://www.bloggingtip.net/pimp-your-adsense-to-increase-your-ctr/
adsense does not have background (it only have solid colour) all you can do is using a picture surround it and make it looks nice. IMHO: is not against TOS but might be
I have seen a lot of Google Adsense in the web and there are a bunch of them using backgrounds. For that I don't think it is against the TOS. Besides who dares to read that a thousand miles long TOS anyway? lol
As I know using background is not supported but if you have enough patience then read TOS carefully before doing it
If you want to make sure contact adsense after you have implemented it and ask them if it is ok. If they say no, remove it. If they say yes, let it stay but keep the email!
I am just wondering, do Google have the time to search those millions of ads whether with or without background? If so, how do they do it capturing those with backgrounds if its prohibited?
Adsense backgrounds have always been ok as long as they are are not misleading, like images above ads were.