Beauty ProtectorBeauty Protector Protect & Blonde Toning Shampoo

BUY at Birchbox

Pop quiz: Which color is best for washing blonde hair? Strange-but-true answer: Violet. This vegan and paraben-free cleanser has a deep purple formula to reduce brassiness, cancel warm tones, and amplify cool tones (so your blonde looks its very best). Bonus: It also works its magic on white, gray, and platinum strands.