Oh, strange. I have decks with the black and grey backs but with white fronts (black and grey pips).
They've got a black and grey (the grey on the box is actually silver like on vipers) box, but the box doesn't show what the front of the cards should look like (I'm in Canada and I've noticed card boxes are usually different here, maybe cause they need the words in french and english.), so I never suspected them of being 'misprints'. I think I have the same deck as you've described, correct me if I'm wrong.