What is the function of a toner in hair coloring?

The function of a toner in hair coloring is specifically to neutralize unwanted tones. Toners are used after the initial hair coloring process to adjust the overall hue and to address any undesired warm or brassy undertones that may have emerged. This is particularly important in processes like lightening where the underlying pigments can result in yellow, orange, or even greenish hues, especially in blonde hair. By applying a toner, which usually contains color pigments, you can achieve a more balanced and aesthetically pleasing shade.

While some products may add volume, lighten hair color, or enhance shine, these are not the primary functions of a toner. Instead, toners are specifically formulated to refine and perfect hair color by ensuring that the final result is aligned with the desired shade.