The Grey's Anatomy star, who is married to Josh Kelley, said that she enjoyed watching him "freak" out when he first saw it too.
Heigl told Us Magazine: "I was pretty shocked at first... I was like, 'wow, it's dark, that's not just brown, that's black.' It took me a good day and a half to totally embrace it.
"[Josh] just freaked out immediately. That's good at least that the boys like it. I love it. It's fun. I feel a bit different even though I don't act any different. I say all the same stupid things - I just look different."