my hair was your color and now its almost black, more of a reddish/black. i found that because i am pale 6 months outta the year black black was too dark, so its more of a burgandy/black, which i like a lot more than when mine was black. its always scary cause black is pretty permanent. i think you could pull it off. keep us posted if ya do it.
Some dark peek-a-boos would look really nice, and slowly make your hair darker and darker. Going from light to dark right away could make you looked washed out. (: