The Story Behind Keira Knightley's Emerald Green Slip Dress From 'Atonement' British Vogue Atonement dress, Keira Knightley, Green Dress UK Velvet Birdcage The Story Behind Keira Knightley's Emerald Green Slip Dress From 'Atonement' British Vogue Vestido Verde Pelicula Expiacion Green Dress Keira Knightley Atonement Dress Expiacion Vestido Anyone else still thinking about Keira Knightley's backless green dress from Atonement, 13 years later? At the link in bio, our style editor examines why the backless trend became an unlikely