Who's that girl? 

Kate Hudson was almost unrecognizable on the set of her new movie, The Reluctant Fundamentalist, on Tuesday in New York City.

PHOTOS: Celebs who made dramatic hair color changes

The 32-year-old star, who is engaged to rocker Matt Bellamy, 33, sported a dark brown hair color (most likely a wig) and frumpy clothes, while she shot scenes with co-star Riz Ahmed. The thriller, which also features Liev Schreiber and Kiefer Sutherland, is set to be released in 2013. See more pics of Kate as a brunette from PopSugar.

Hudson and Bellamy have been living in his native England while the Muse frontman records a new album. This is the actress' first film sincre the couple welcomed son Bingham in July.