The natural blonde Mad Men star changed her hair colour early in her career.
What was meant to be a look for a photo shoot led to many others as the flaming hair set her career on fire too.
"When I first started modelling I was blonde. Then I got a job and they wanted to do my hair bright red," the actress is quoted by the Daily Mail as saying.
"I'd always wanted to, but the head of my agency was like, 'You look terrible, it's so ugly, you cannot have red hair'.
"I came back as a redhead and couldn't get my hair back to blonde for two days in the meantime, I had to audition.
"I booked two or three jobs, because there were a lot fewer redheads than blondes, and I was like, 'This is working for me, I'm keeping this!'"
Christina also credits her vibrant hairdo for helping her land major movie roles, such as the 2011 Ryan Gosling action film Drive, and her most recent project Ginger & Rosa.
She believes, and we agree, that her hair ensures people remember her.
"I think it does make you stand out. People remember you when there's a sea of faces. It helps," she said.
Although we think it’s not just her hair that's the most memorable part of Christina's look.
Her famous curves have also propelled her to iconic status in Hollywood not to mention that awkward Kate Waterhouse interview (more details in the video below).