OnePlus has come to its first CES event to unveil the Concept One. This device is built around the idea of color-shifting glass, and how it can be integrated into a phone to hide the main cameras while not in use. This material is found in a backing that also features leather in the OEM's brand-partner McLaren's signature shade of orange.
https://www.notebookcheck.net/OnePlus-unveils-the-Concept-One-its-first-Electronic-CMF-phone.449470.0.html