Allison Williams & Shay Mitchell: CNN Heroes' All Star Tribute!

Allison Williams is a purple hottie while attending the 2013 CNN Heroes: An All Star Tribute held at The American Museum of Natural History on Tuesday (November 19) in New York City

The Girls actress was joined on the red carpet by Pretty Little Liars Shay Mitchell at the Anderson Cooper hosted event, which honored everyday people changing the world.

PHOTOS: Check out the latest pics of Allison Williams

Last week, Allison was classy chic while attending the CFDA/Vogue Fashion Fund Finalists Celebration.

FYI: Allison is wearing an L’Wren Scott dress. Shay is wearing an Alaia dress and Saint Laurent shoes.

20+ pictures inside of Allison Williams and Shay Mitchell attending the CNN Heroes: An All Star Tribute…