New 50+ Lily James Cinderella Blue Dress. The dress is elie saab couture, and with long sleeves, plenty of sparkle, and a construction that looks light as air, it totally feels like the kind of magical number a fairy godmother would whip up for you to wear to the party of. Cinderella's dress boasts countless layers of tulle on the petticoat and no less than four miles of thread. Lily james's powder blue shimmering gown was embellished with over 111,000 finely cut swarovski crystals.