We've seen Sienna Miller  test-drive a bevy of hair colors (including her most recent rose gold moment ), but she recently stepped out with a hue we can't remember ever seeing on her before. Sienna hit the beach with fiancé Tom Sturridge and daughter Marlowe  with some red hair that almost distracted us from her smoking bikini body. We haven't heard of Sienna being attached to any movie projects right now that call for a redhead, so maybe she just wanted to try it out. How do you think the color works for her?
See more exclusive photos of Sienna's beach vacation on POPSUGAR !