He shut his eyes but, instead of praying for inward strength now, he found he was just looking at the strange reddish dark and the little flashes and floaters in there that got almost hypnotic when you really looked at them.

NEWYORKER: Wiggle Room

He looked tired and drab, his eyes rimmed with dark circles, a reddish stain disfiguring his crisp white polo shirt.

NEWYORKER: Raj, Bohemian

This new genetic approach is also able to differentiate between some hair colours that are similar, for example, between red and reddish blonde, or between blonde and dark blonde hair.

BBC: Hair colour predicted from genes