Panettiere checks out the newly blonde Rumer Willis's 'do. Plus: Justin Timberlake, Hilary Duff and more

THE BLONDE VOTE

Hayden Panettiere welcomes a newly blonde Rumer Willis to the platinum club at the Declare Yourself, Hollywood Turns 18 party Thursday at the Beverly Hills Cultural Arts Center. Willis told PEOPLE of her shocking new look: "Everyone, my parents, loved it."