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Google looks to be testing changing the ad label in their search results once again. The last time they changed it was in February 2017, when they went with a green outline ad label. This new test shows small black text labeled as "Ad" and that is it.
Before that it was a green to yellow label and so on.
Here is a more full size screen shot, which is more of a picture of a phone from Matthew Norman on Twitter who took it from Darren Taylor on LinkedIn.
Here is what I see:
It wouldn't surprise me if Google looks to change the ad label. They like to change things up with their ad labels every now and then to drive more eye balls to the ads.
Forum discussion at Twitter & LinkedIn.
Update: Here is another screen shot from @yvoschaap, this one shows Adv. in black:
