Sienna Miller  is best known as a blond bombshell who rarely strays from her golden roots. That's changed for her new role, though. The actress debuted freshly dyed red locks  on the set of her new movie, American Sniper, on Tuesday, just weeks after we last caught a glimpse of her signature look at Kate Moss's star-studded Topshop launch . The actress isn't a complete stranger to the fiery shade — in January, Sienna's hair was red during her bikini-filled family vacation .
With her new look front and center, Sienna has been busy filming scenes with her handsome costar Bradley Cooper , who has also experienced a transformation for the movie. Earlier this month, Bradley showed off his new beefy body  before he suited up for the Met Gala . Keep reading to see Sienna and Bradley's new snaps!