After turning heads with her new casual chic in New York, Katie Holmes returned to her usually glamorous self at the Tropic Thunder red carpet in Los Angeles. But no one could figure out who designed Katie’s fabulous navy dress — was it Lanvin? McQueen? It turns out the designer of the dress was none other than the star herself and her stylist Jeanne Yang! Though this original Holmes Yang design has gotten rave reviews, Holmes’s rep tells PEOPLE that there is no line in the works. Too bad — we’d snap up one up for ourselves!