Katy Perry and Selena Gomez put on their party finest for last night's UNICEF Snowflake Ball at Cipriani 42nd Street in NYC. The girls hit the blue carpet before heading inside for dinner and mingling. Katy wore a Naeem Khan caped ensemble, while Selena showed a bit of skin in Dolce & Gabbana. It was a colorful night for the female attendees — Kate Mara donned orange Jason Wu, Uma Thurman picked a dark blue Atelier Versace gown, and Girls star Allison Williams picked a mint green Naeem Khan ensemble. The night was about doing good, and quite a bit of charity took place. Selena tweeted, "So proud to be a part of UNICEF — we raised 2.5 million dollars tonight!"