Dye precursors
Color precursors are pigments that have a small molecular size and therefore can penetrate deeply into the hair. Color precursors are included in any permanent hair color and ensure that grey hair can be completely covered. The pigments are undeveloped on penetration into the hair structure and an oxidative process is triggered only by the addition of hydrogen peroxide (H2O2). In this process, the colorless dye precursor is first developed into a visible pigment. Other hair dyes without color precursors for example semi-permanents color work with so-called direct colors in which the pigments are already predeveloped. Due to their size they can only deposit on the hair surface and not penetrate deeper into hair structure. For this reason grey hair with hair tints can not be completely covered and the hair tint washes out of hair after a few washes.
Unlike permanent hair colors where the pigments first penetrate deeply into the hair structure and develop there into visible pigments. These can not be washed out but the colored hair grow together with natural hair growth.
There are two types of color precursors each containing a different amount of color. The oxidative hair colors consist of two different groups, the color precursors and the color couplers. In addition, oxidative hair dyes sometimes also contain direct / temporary color pigments which deposit on hair surface. The result is a very intense color and a unique shine.
The process of hair dyeing is very complex and requires a good allocation of the initial hair color. Learn more about hair coloring and hair tones in our beauty glossary.
