In 2007, Google changed the long-standing shaded background indicating the ads section of the page from blue to yellow. In 2008, it then briefly tried a green background before reverting back to yellow. Google continued to test variations of background colors including bright blue and a light violet. In 2010, violet officially replaced the yellow, but only lasted about a year before yellow reappeared in 2011. In 2013, Google tweaked the yellow to a paler shade, which would close out the era of background shading.

At the end of 2013, Google removed the background shading and began testinga yellow ad label next to each text ad. The yellow “Ad” label rolled out globally in 2014 in a much smaller size than first appeared in the initial testing. In 2016, a new green label marked the first time the color of an ad demarcation matched the color of an element in both the ads and organic listings: the display URL. A year later, Google kept the green, but inverted the treatments so that the font was green with a thin green border on a white background. This year’s update to the black label does away with the border altogether. The display URL is now black to match the label. —Ginnny Marvin, Search Engine Land