To date, Google’s dark themes have faded more than pitch / AMOLED black, which some have preferred. Google is now testing a completely black theme for search on the desktop web.
Instead of dark gray, the background of the search results pages changes to # 000000. Links and other colors of previously viewed pages are similarly tweaked to make them a little bolder and less muted.
For those with this A / B test, the google.com homepage has not been modified and still uses a light gray color, while the Quick Settings panel changes this new black to just a “dark theme”. Explains
Visually, Google’s gray theme is better for being less grumpy, especially when it comes to inevitably visiting light web pages. If Google decides to use Search Black, hopefully the company will retain the old dark theme as a user-selected option.
This change is appearing in some users these days, but not all. In fact, the first people to get the theme lost it. Rollout does not appear to be specific to any operating system.