Phones with Colour spectrum sensor

This is not the main sensor that records the photo: it does not image the frame directly but takes a supporting measurement for the main camera, and the result is used while the main frame is processed.

A colour spectrum sensor measures the colour of the ambient light and sets the photo's white balance from that measurement. Because it measures the light directly instead of guessing from the camera's own image, it is more accurate in the cases where a large single-coloured surface — a red wall, a green lawn — makes the camera read colour wrongly.