The actress stunned at Vanity Fair and Barneys New York's private "Spotlight" dinner celebrating the film's director, Tom McCarthy, at Chateau Marmont in Los Angeles on Wednesday.
McAdams looked gorgeous wearing a chic royal blue midi dress, complete with edgy shoulder cutouts. She finished her look with nude pumps and added a pop of color with a bright pink lip.
Rachel likewise showed off her new platinum 'do at the event -- just in time for the 2016 Academy Awards! Though the "Notebook" actress normally sports a golden hue, we're definitely not hating her mini hair makeover. Think it has anything to do with "Doctor Strange," which is currently filming?
During the dinner, the 37-year-old also posed for photos with her "Spotlight" costar Mark Ruffalo. The pair were spotted hugging one another at the celebrations, where they were joined by McCarthy and Sam Smith.
Rachel's nominated for Best Supporting Actress for her work in the drama and we can't wait to see what she wears to the award show Sunday night.
What do you think about McAdam's new hair color? Sound off below and check out the gallery above to see more stars who've gone blonde!