Like a maid of honor upstaging the bride, Kristin Scott Thomas stole the show as she glided into the premiere of Juliette Binoche’s new film, “Cache,” at the Cannes Film Festival last Saturday. Dressed in a peacock blue, custom-made silk, cashmere and organza Yves Saint Laurent gown that perfectly offset her pale complexion, Scott Thomas oozed cool glamour. “There is an abundance of talent and elegance in Madame Scott Thomas, as well as an intriguing personality,” says designer Stefano Pilati, who played with transparencies, draping and multiple panels in crafting the modern column, inspired by his fall 2005 collection. Scott Thomas was in Cannes to promote “Chromophobia,” the latest from British director Martha Fiennes, in which she stars along with Martha’s brother Ralph Fiennes, Penelope Cruz and Ben Chaplin. Though the film holds the honored closing spot in the Cannes schedule, it appears Scott Thomas has already made her premiere. Just don’t invite her to your wedding.