Google search has been experimenting their new look since November of 2013. Initially, it was limited up to the appearance of Ads but now implemented for the whole page. This experiment had begun from the mobile platform since September of 2013.
The user will no longer feel light pink shading behind the Ads. Right now, they are looking more plain and simple, preceded with simple yellow themed 'Ad' tag. New implementation removes the underlines from search results, along with enlarged font size. This new look is part of Google's major change in this year.
Amit Singhal, Google's senior vice president of search, has illustrated of this modification in their official web blog.
"It’s cleaner and simpler, optimized for touch, with results clustered on cards so you can focus on the answers you’re looking for,"It's an indication of Google's continuous experimenting with look and feel. Hope this major change will fetch fruitful results in the future.One point to note here, Google made all these changes without losing their inherent policy of simplicity. So, you may call it, "New wine in the old bottle".