AdSense have emailed publishers today telling them that they’ve changed their default ad design to be a borderless ones. Their email reads:
“We’re writing to let you know about a coming change to the appearance of your Google ads. Your ads currently display the default Google color palette, Seaside (formerly known as Mother Earth). In the near future, we plan to update the default palette to Open Air, a new palette containing the same set of colors, but without the blue border. We’ve found that many publishers prefer the cleaner look of this palette and have also seen that a blended color palette performs better for them — attracting user interest while still maintaining the distinction between ads and content with the ‘Ads by Google’ label.
Please note that this change will only affect your ad units where your ad code does not specify colors. For all other units, your color selections will be retained.”
They then went on to outline the steps of logging into AdSense palettes to make the changes.
I’ve not considered this before but now that they mention it I’m surprised they didn’t do this earlier.