Google does go back from its black navigation bar
Google changed the bar across the top of their products to black in June as part of their across the board redesign with Google+. From what I read, not many were fans of the high contrast change.
The redesign is now entering its next phase according to the official Google Blog.
Instead of the horizontal black bar at the top of the page, you’ll now find links to your services in a new drop-down Google menu nested under the Google logo. We’ll show you a list of links and you can access additional services by hovering over the “More” link at the bottom of the list. Click on what you want, and you’re off.
For more information about the latest interface change, you can refer to this Help Center article which explains the new dropdown-on-hover and other features of the new Google Bar.