Billie Eilish Went Strawberry Blonde for a Halloween Tribute to Jane Fonda

Eilish was spotted attending Kendall Jenner's Halloween party at the Chateau Marmont over the weekend dressed as a cowgirl, wearing the blue and white gingham shirt, brown pants, and matching cowboy hat of Cat Ballou. Under the hat wasn't the singer's usual pitch-black and vibrant red hair but, instead, wavy, strawberry blonde hair with long, side-parted bangs.