Keira Knightley turned heads in a green tulle Valentino gown last night Keira Knightley at 'The Aftermath' premiere Keira Knightleys green dress in Atonement (2008) was designed to embody desire, elegance, and envy. Flowing and sultry, it enhanced the passion of the library scene while its striking shade of A dress so iconic the original went missing! , Keira Knightleys emerald silk gown in Atonement wasnt just the green dress it was the moment. Custom dyed, cut on the bias, and so delicate it tore The green dress which Keira Knightley wore in Atonement (2007) has been named "the best of all time" by InStyle Magazine, exceeding some classics as Audrey Hepburn's little black dress in Breakfast