I like colored stuff. Not only are white and yellow (and to a lesser extent, orange and red) easier to see in low viz, but colors make other divers easier to sort out. There is nothing worse than having eight or ten DIR divers converge on an octopus in the dark -- everybody in a black drysuit, grey doubles, black hood, canister light, Jet fins. I like to go home with the person I came to the party with, and colors make that easier to do . . .