COLORLESS manga volume 1 features story and art by Kent.

A cosmic disaster changed the Earth forever, stripping away every last drop of color from the world. Mankind also changed: the familiar human face is almost forgotten in a world now populated wholly by mutants. Against the backdrop of a moody urban landscape, a lone-wolf investigator named Avidia relies on both his wits and extraordinary gun to hunt down the world’s last hidden scraps of color. He soon crosses paths with a very special girl–one who just might hold the key to bringing back what the world has lost.