The Collaborative International Dictionary of English v.0.48:
charcoal-gray \charcoal-gray\ charcoal-grey \charcoal-grey\adj. very dark gray. Syn: charcoal. [WordNet 1.5]WordNet (r) 3.0 (2006):
charcoal-grey adj 1: of a very dark grey [syn: charcoal, charcoal-grey, charcoal-gray]