Realm of Chaos: Slaves to Darkness (1988), p115 — 191-195 Black Skin

The mutant's skin becomes completely and unremittingly black, so that even light falling on the mutant vanishes into the depths of its darkened surface. Its eyes, however, turn milk-white and lose their pupils and irises. The mutant's sight is unaffected by this alarming change. The mutant's physical make-up is otherwise unchanged; only its colour is altered. Add one to the mutant's fear points.

WFRP: +20 to hide tests at night or in dark surroundings.