Amy Adams says she had to change one big thing about her looks to make it in Hollywood.

Wildly successful actress Amy Adams says her acting career may not have been possible if it weren’t for her hair colour.

Yes, you read that right. Her hair colour.

The 42-year-old, who you might recognise from films such as Enchanted and American Hustle, believes her rise to the top is largely the result of sacrificing her natural blonde hair to become a redhead.

“Based on roles that I was getting, called in for, people were responding to certain types of characters with me as a blonde and the minute I went red, it was quirky and fun instead of flirtatious and dumb,” People reports the mother-of-one said at New York Times' TimesTalk event on Wednesday.

While Adams is aware that the change was far from monumental, she's still amused by how much perception relies on appearances.

“It was great, I liked that. But in all seriousness, it’s just hair colour," she said, adding: "It was really fascinating to see just one element of yourself change people’s perception and that became a very powerful tool for me even in my acting."

Fascinating, but also sad to see yet another actress confirm just how important even the most basic details of your appearance are to make it in showbiz. It's time for change.

Have you ever changed your look for a job? Let us know in the comments.