The 27-year-old actress feels much more comfortable now she has brunette locks and claims it has affected the way people treat her.
She said: "I'm a natural blonde, but I feel like a brunette. I feel people treat me now how I should be treated.
"People used to be shocked, when I was a blonde, that I wasn't stupid."
Olivia changed her surname from Cockburn after graduating from college and claims her family supported her new moniker as it gave her an identity of her own.
She explained to GQ magazine: "My mother thought it was a good idea for me, so I could have my own identity outside of my family."
Last year, the actress starred in 'Tron Legacy' with Jeff Bridges, and she admits she was in awe of her co-star because of his previous role in classic movie 'The Big Lebowski'.
She said: "I had to stuff my fist in my mouth not to ask 'Lebowski' questions."
Guess the only state in the US where an Irish last name ranks in the top 3