A WebmasterWorld thread is reporting one user seeing the background color of the Google AdWords ads for the features ads as being gray pink and not yellow.
Now, we have seen Google move from the old blue background to the yellow one in 2007. We have also seen Google test green backgrounds and then even test going back to a flavor of blue and yellow backgrounds together.
But now I am seeing reports of a gray background behind the AdWords ads. I have not seen it myself, nor have a seen a screen shot, but I do hope to post one as soon as someone sends one to me.
There are even additional reports in the WebmasterWorld as seeing a "light pink background" but that might be similar to seeing blue by someone with color blindness?
In any event, have you seen the gray background?
Forum discussion at WebmasterWorld.
Update: Here is a pink background picture from @marcoziero: