Dita attended the Paris Fashion Week Haute Couture Fall 2011 Closing Party at Trianon Palace on 7 July. She wore a long black velvet gown with an pale blue satin bodice, intricately beaded and embroidered in gold, and with sequined pale-pink tulle flowers on the shoulders and cascading down the skirt by Alexis Mabille, which incidentally was also worn by Leighton Meester in Gossip Girl season 4.
The dress was from Alexis Mabille's Fall 2010 collection. You can see the beaded/embroidered detail down the front much better in the runway shot.
And here is a closeup of the bodice. Click to make it much bigger. Look at all that work! Gorgeous.