Need help with Google Adsense

I am using Google Adsense to monetize my website. I want the ads to blend into the UI seamlessly. As if they are a part of the UI itself. Now that is the case for most of the ads Google Adsense provides but for some, like this one, the background is gray. Or some other. I would like the background of the ad to be fully transparent, all the time, for it to look like truly a part of my actual UI. Is there a way I can do this? Tell google to always send a Background-Transparent ad? Set the background to transparent manually through my CSS/JS ?