OnePlus has unveiled a new concept smartphone called the OnePlus 8T Concept. It's based on the recently launched OnePlus 8T, and showcases some of the tech the firm has been working on. The 8T Concept gets a colour-changing film under its rear glass, that can change its colour from silver to dark blue, for things like notification alerts. It also gets a mmWave radar system, that helps the phone perceive, image, locate and track objects, that OnePlus says can be used to detect hand gestures and monitor a person's breathing.