Alyson has natural auburn hair, but she colors it to get her signature red hue. It's all because of her role as Willow Rosenberg in Buffy the Vampire Slayer — and something she had in common with costars Charisma Carpenter and Sarah Michelle Gellar.
"Joss [Whedon] had us all over to his house," Alyson says. "Charisma and Sarah and I all had brown hair at the time. Joss said, 'All of your hair is kind of the same shade. Does anyone want to be red?' I went for it. Eventually Sarah got more and more blond, but it was because we all had a brownish, auburn mane."