I think it should look fine, and the Flayed Skull already use an off-white bone color as an accent for their helmets and the like.
I'd say try it. If you don't like it (and you've been keeping your paints thin) you can always paint over it. A Reaver might be a good choice to experiment on.
Dark Eldar plog: Drug-Crazed Space Elves
Stupid humans plog: Calyptra's Stupid Humans
Vampire Counts plog: Bat Country