O to the M to the G. The biggest show of Fashion Week — Marc Jacobs, hello — walked tonight at the New York Armory. We were invited backstage a few hours beforehand to steal a peek at the design demigod's hair (Redken), makeup (Nars), and nail (CND) choices. What we saw: wildly frizzy disco-glam hair out to there, nuder-than-nude fingernails, deep-red toenail polish, bleached eyebrows (which actually look prettier than they sound), and forest-green eyelids. Watch the video to see how all the elements came together.

See more: Marc Jacobs's Spring 2011 Collection