Mary-Kate and Ashley Olsen celebrated the opening of their LA flagship store, Elizabeth and James, with their younger sister, Elizabeth, at the Chateau Marmont hotel on Tuesday evening. Mary-Kate dressed in her signature black attire, while Ashley switched things up in a white trench coat and sported a blonder 'do. At the event, the Sisters posed for pictures and mingled with a handful of their famous pals, including Heidi Klum and Erin and Sara Foster. While Ashley and Mary-Kate opened The Row boutique in 2014, this is their first LA store for their Elizabeth and James fashion line.