Christelle Baillet for Vogue writes: A unique limited edition collection from Proenza Schouler and must-have backstage make-up brand M.A.C. is the hottest new collaboration of the moment. Every season Jack McCollough and Lazaro Hernandez rely on M.A.C. backstage at their shows, but today it is the make-up brand that is giving them carte blanche. A new 15-piece collection features a sunset-effect palette, metallic eye shadows, eyeliners and urban color varnishes,...