Hair toner is a product used on hair after it has been subject to bleaching and lightening process in order to get rid of brassy and grey tones.
Using toner treatments will turn your hair into a better blonde or lighter brown depending on how your previous colour treatment has left your hair.
Toners work most noticeably on light hair as it does not lift permanently after the colour of the hair but adds a tone over it – so great for eradicating brassy and bad tones.