Katy Perry is going 1920's retro glam to promote GHD's latest hair campaign for their Scarlet Collection.

The sexy 26-year-old songstress is channeling Snow White with black short hair, plum-colored lips ... and even holding a poisonous apple. Wickedly delicious!

David LaChapelle brilliantly shot the sexy photo in a dark and dramatic fashion. Click thru to see Katy's other pic from the campaign where she's rocking a pink feathery outfit.