Thom Browne’s debut at Paris Couture Week was a theatrical, melancholic extravaganza, with some arch humor bubbling under the uniformly gray surface.
During a preview, he had mused about his signature flannel suits invading the hallowed high-fashion arena. No kidding: There were 2,000 cardboard cutouts of men in gray suits seated in the Opéra Garnier when the curtain went up. (The audience, including actress Diane Keaton and rapper…