I guess I can be a bit of a good-natured contrarian... I have a yellow UK C8 light, but I think if I had it to do over again I might have bought black. The main reason is, that if a panicked OOA diver comes swimming full tilt at me, they're lookingfortheyellowthingtheyellowthingohmygodwhereistheyellowthingtheoctotheoctoyellowTHERE! and grabs my light instead, and then REALLY freaks out when they realize they can't breathe from it. But since it's always clipped on, with a spring lanyard, it's highly unlikely that I'll lose it.
But, ehh... if I *did* drop it, a black light would be pretty much impossible to find, even here in the crystal-clear lakes of Texas. And, since I only carry my big primary light at night, they probably wouldn't see it (or the octo) anyway.
Final answer (for me): It's not a big enough deal to change lights, but I were doing it again, the black light would win by a nose.
--'Goose