Classic Gray is a dark mid-tone gray. The oak will require sealing so that tannin pull doesn't turn the gray yellow. And a clear coat (not Minwax) will have to be applied so that your gray floor doesn't turn ORANGE.

Ebony is so dark...nothing matters. It can be "black" or "charcoal" and would act very much like a painted floor. The sealant and finish won't matter...because no one would see "orange" sitting on top of black.

What did you end up going with? Any photos?