Nicole Richie has dyed her hair gray. The 31-year-old fashion designer showed off her newly-silver tresses at the Met Ball at New York's Metropolitan Museum of Art last night, sticking to the Costume Institute Gala's Punk: Chaos to Couture theme by matching her updo and white Topshop column dress with a red and gold manicure, multiple gold earrings and a dark burgundy lip.

Nicole - who has five-year-old Harlow and three-year-old Sparrow with husband Joel Madden - had earlier teased fans about her change of look, posting pictures of hair extensions lying on a bush and a bowl of dye onto her Instagram account. Alongside the pictures, she wrote, "Even the bushes have extensions! Happy Met Ball Monday!
Hair Time #MetBall (sic)"

And the Fashion Star host wasn't the only star to change their hair for the annual fashion extravaganza.

Anne Hathaway - who shaved her head for her role in Les Miserables - showed off a short blonde crop, which she admitted she wanted to keep forever, though she knows she'll have to revert back to her famous dark tresses soon. Anne - who wore black vintage Valentino - said, "It's temporary. But as soon as I did it, I thought I didn't want it to be temporary any longer. I know I have to dye it back for my work."

And Kerry Washington teamed her low-cut purple, black and blue Vera Wang gown with long leather gloves and purple streaks in her hair: "In honor of Vera's design I put all these purple highlights in my hair to have a punk moment. I've never done anything like this before in my life!"