If you don't have black you can't achieve metallic effects... If you disagree, please explain how it is possible to achieve said effect without black.

As far as I know, and I was pretty deep into this at one point, metallic requires black and without it you cannot achieve any sort of luster-like effects.

Ah, "you have no idea" as in "that is more correct than I think you realize", but maybe you do. Not meant as an argument; more as hyperbolic.