A Google Twitter account for Nexus devices (@googlenexus) actually tweeted a screenshot of possibly an update to the Google Dialer app. The Google support tweep was trying to explain a user how to see details of a call log but took a screenshot of a pre-release app.
The current Google Dialer app is entirely white with minor shades but the picture tweeted showed a blue action bar.
This screenshot shows that Google might be doing a large a major overhaul to either the android design
Just in case you want to know how the current /old Google Dialer looks like, below is a picture
Source: Android Police