Black and white are both great with those. For any other ideas, you would have to show other elements of the bathroom. Is this a family bathroom or a master bathroom? I would never use black in a family bath, it would be too hard to maintain. Maybe a couple would do better. If you use powder, though, don't do black! A dark gray that goes well with yours would be good, too. You would have to go to the paint store and start looking, then bring home several to look at in your light.

Black always looks smart with marble.

Sure, if it looks good with the paint. It would have to be a few shades darker. Since Gray Owl, on the card with the progressively darer shades, looks like it is a greige, the darker colors become brown. So you would have to go to the paint store and find a charcoal that looks good with the greige color. If you go to the Benjamin Moore site (google Benjamin Moore Gray Owl) they will lead you to look at the color in different rooms, and it you go to where you can change the colors for the different elements in the room you will get the chance to see the Gray Owl with other colors. I see it with Silver Spring 2120-50 and it looks great,, a darker gray that will look nice with Carrara. Not Charcoal, but charcoal is awfully dark.

This is from that site and it purports to show Gray Owl walls and Silver Spring doors and fireplace. It is worth a look, as the combo looks like it might go nicely with the Carrara. Your veins are quite dark, so might take a darker color. You are there and you can see, we can't, go to the paint store and see what looks good with the marble, take a sample with you to pick out the paint.