The stunning actress, famed for her long blonde tresses, dyed her locks for new movie G.I Joe: Rise of the Cobra and was thrilled with the results.
Sienna, who is sporting honey-coloured hair again, is quoted as saying: "I actually loved the dark look. The worst part was going back to blonde afterwards from such a dark colour but it's back to normal now. I keep thinking though that I might dye it again. It's fun to have that change." Sienna, 27, recently revealed her delight at the news she is being turned into a doll.
The beauty - who played poet Dylan Thomas' wife in The Edge Of Love - is thrilled to be immortalised as a plastic action figure in the guise of her character Baroness.
She said: "I don't think anyone, anywhere would be playing with them if they were for The Edge of Love but G.I. Joe is a whole new experience. "I'm not sure if I'm going to be playing with my own doll - but I'm going to have happy nieces and nephews, I'm sure."