berto - 2:12 am on Jan 3, 2006 (gmt 0)
I have YPN ads with beige background to match my page background color. Yahoo! serves "Ads by Yahoo!" as white text, which is barely discernible on the beige background. In this situation, Adsense would default to some darker color to make the text stand out. If Yahoo! defaults to a lighter, unreadable default color, that's their problem, not mine.