© Getty Images

Sofia Vergara -

The Colombian actress is actually a natural blonde, but according to her it wasn't working in her favor at auditions.

© Getty Images

Sofia Vergara -

Dying her hair was a game-changing move. She went on to become a household name thanks to 'Modern Family.'

© Getty Images

Leighton Meester -

The actress was actually blonde when she auditioned for the role of Blair Waldorf in 'Gossip Girl.'

© Getty Images

Leighton Meester -

Meester dyed her hair on purpose for the role and never looked back.

© Getty Images

Alyson Hannigan -

The actress stared her career as a brunette. And then she was cast in 'Buffy the Vampire Slayer.'

© Getty Images

Alyson Hannigan -

Hannigan has been rocking red hair ever since, and her career really took off after the role.

© Getty Images

Olivia Wilde -

The actress, who's a natural blonde, believed that her hair color was somewhat limiting her career.

© Getty Images

Olivia Wilde -

"When I went brunette, the roles went to more, ‘She’s a waitress with a heart of gold, and a tough life,’ or ‘She’s a doctor.’ And I always wondered—would I have been offered those roles had I still been blonde? I don’t think so," she said.

© Getty Images

Dakota Johnson -

You might remember the actress from movies such as 'The Social Network' and '21 Jump Street.'

© Getty Images

Dakota Johnson -

But Johnson's popularity didn't skyrocket until she cut her bangs and dyed her hair brunette for her role as Anastasia Steele in 'Fifty Shades of Grey' (2015)

© Getty Images

Emma Stone -

The actress is a natural blonde and used to dye it brunette when she was younger. It was not until she auditioned for 'Superbad' (2007) that she dyed her hair red. 

© Getty Images

Emma Stone -

"When I went to the camera test for 'Superbad,' Martha MacIsaac, who was the other girl in the movie, had brown hair. Judd Apatow (the producer) walked in and said, 'Make it red,'" Stone recalls.

© Getty Images

Marilyn Monroe -

Before she became hugely famous, Norma Jeane Mortenson was actually a brunette.

© Getty Images

Marilyn Monroe -

Then her modeling agency suggested she should go blonde, and the rest is history!

© Getty Images

Brigitte Bardot -

The actress did not start her career as the iconic blonde bombshell we came to know and love.

© Getty Images

Brigitte Bardot -

It was not until 1956, when she was cast in 'Nero's Mistress,' that she dyed her hair blonde.

© Getty Images

Gwen Stefani -

The singer is not a natural blonde. She dyed her hair when she was in high school and her career with No Doubt started to take off.

© Getty Images

Gwen Stefani -

"I remember my boyfriend and I had just broken up, and I was like 'I don't care how much it costs, I'm getting my hair bleached! That's really when everything changed," said Stefani.

© Getty Images

Christina Hendricks -

Christina Hendricks started her career as a model, and she had naturally blonde hair. Then she dyed it red for a photo shoot, and never looked back.

© Getty Images

Christina Hendricks -

"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," said the 'Mad Men' star.

© Getty Images

Amy Adams -

The actress is a natural blonde, but dyed her hair because she was getting typecast as the "bi***y girl."

© Getty Images

Amy Adams -

Adams dyed her hair red, and ever since has become a top A-list star.

© Getty Images

Mandy Moore -

You might not remember the singer and actress like this, but Mandy Moore is actually a natural blonde.

© Getty Images

Mandy Moore -

"There was a real significance to coloring my hair. As silly as it sounds, there was a real significance in the way that people saw me, but also in the way that I carried myself and that I saw myself," revealed the 'This Is Us' star.

© Getty Images

Deborah Ann Woll -

Deborah Ann Woll is a natural blonde, but she found success when she dyed her hair a different color.

© Getty Images

Deborah Ann Woll -

The 'True Blood' actress became famous with her red hair.

© Getty Images

Lucille Ball -

The actress was in fact a brunette when she started her career.

© Getty Images

Lucille Ball -

Ball then dyed it for 'I Love Lucy' and became one of the most famous redheads in pop culture history.

Sources: (StyleCaster) (Ranker) (Marie Claire)

See also: These male celebs all dye their hair

© Getty Images