Insider has tested Function of Beauty's personalized haircare routine before and our opinions were mixed, so I was intrigued to see it launch a new purple shampoo and conditioner. Between salon ...

Blonde hair, for example, is strengthened and enhanced by purple shampoo, while brunettes benefit from the neutralizing effects of blue shampoo. But what about red hair? The best shampoos and ...

L'Oreal Paris Ever Pure Purple Shampoo and Conditioner is on sale for $16, and celebs including the ever-beautiful Andie MacDowell are fans. What makes these inexpensive problem-solvers so unique?