Anthracite?

If you do a search on either: Anthraclub or anthracite, you should come up with loads of threads showing the colour(S) in its many guises. It varies from a dark dark grey with blue sheen or green sheen depending on the light and on the bag itself as some bags are markedly different form each other. I described it as a sort of granite-like in that I see so many shades within, a chameleon.