New Delhi, Dec 21 (IANS): Smartphone brand OnePlus is working on a concept smartphone that changes colours as you breathe, and sports a motion-tracking radar tool.

According to the company, it is using a technology called Electronic Color, Material and Finish (ECMF) for the OnePlus 8T concept phone.

The technology uses a colour-changing film that contains metal oxide in glass.

When that metal oxide is activated, it's able to change colour from a dark blue to a silver one.

The radar could sense your breathing and change the back's colour in time with it, "effectively making the phone a biofeedback device".

"The new module, which is built into the camera bump on the back of the phone, uses millimeter wave radar to bounce electromagnetic waves off its surroundings and lets the phone "perceive, image, locate, and track objects," The Verge reported.

The technology sounds similar to the Google Pixel 4's radar-enabled Motion Sense technology.

This concept phone can also use this motion tracker to do simple things like answering a phone call with a gesture, or offer more advanced functionality like sensing a user's breathing.