New St. Patricks Day themed ads have arrived from AdSense. The ads keep the borderless style if you have seemlessly integrated them with your background (if you use borders, they will stay the same), but they have added green text and a Google Doodle of shamrocks on the right side of the background. They are geotargeted (for example, I cannot see them in Canada, I had to use a proxy) and they do not show on every page view, but here are some screenshots of the ads.
Not all ad units seem to be St. Patrick-cized though. And remember, sites must be opted into the themed ad units in order to show the ads. A nie follow-up to the previous themed ad units.
Forum thread at DigitalPoint.