Have you ever looked at a chameleon and thought, "Why can't my smartphone do that?" Vivo apparently has, and is working on a smartphone prototype that can change color using electrochromic glass. This is the same special material OnePlus recently used to hide a smartphone camera. But while OnePlus only covered the camera module in this fancy glass, Vivo has made the entire back panel out of the stuff, showing it off on video earlier this week.

Video: Vivo

Electrochromic glass is clever stuff, containing several layers made up of tungsten and other exotic materials. These layers respond to changes in electrical current, altering the glass's transparency, or even color. We typically see this used in windows and skylights, where adjusting its opaqueness limits how much sunlight can stream through. Vivo's demonstration shows an unknown prototype changing from silver to various shades of purple. A color-changing phone is definitely unique, and I have to say that I quite like the idea of changing how my phone looks without having to buy cases or skins. If Vivo could somehow make this react to the user's body temperature, thereby resurrecting the mood ring craze, that would be even better.

As cool as this is, we probably won't be able to buy a phone like this anytime soon. The big issue is cost — glass is already on the expensive side of smartphone materials, and adding layers of tungsten is only going to drive that price up, as is the hardware needed to pass a current through it. Although it may be a while before we all carry color-changing smartphones in our pockets, it's a cool concept of what the future of phones could look like.