Rooney Mara was "really excited" to get her long tresses back.
The actress had her famously luscious locks sheared for her role as introverted computer hacker Lisbeth Salander in The Girl with the Dragon Tattoo.
Rooney was recently spotted on the set of her new film The Bitter Pill with lengthy, lighter, hair extensions. The star's stylist Kristina Barricelli says Rooney didn't find the transformation as traumatic this time round.
"Rooney was excited that she was unrecognisable - even her driver didn't recognise her on the way out of the salon," she told People. "She was really excited because she'd never tried extensions."
Rooney's hair was styled by Kristina's sister before hitting the film set. The hair professionals were cautious to avoid damaging the star's hair with the drastic colour change.
"She made it possible to take her from jet black to ombré without ever compromising the condition of Rooney's hair," she explained, before adding that experts at a colour lab dip-dyed the extensions to match.
"She needed to look like a dishevelled woman that is battling deep depression for her role. We decided ombré would give her the opportunity to look chic on the red carpet but still look unkempt for the movie. It was a perfect solution for her."
Rooney will be sporting her new hairstyle until she's finished shooting for her new movie. Kristina hopes to see a new side of the 27-year-old beauty.
"So it'll be fun to see her play with her new hair," she said.