Wella hair toner, a type of demi-permanent hair dye, is a versatile tool used by hair stylists. For instance, using a purple toner can neutralize unwanted yellow or brassy tones in bleached hair, creating a cool, ashy finish.
Beyond hair color correction, toners enhance hair's vibrancy and prolong the life of hair color. Historically, the development of ammonia-free toners led to reduced hair damage and increased versatility.