What Pigment Is Used In Hair Dye?
The pigment used in hair dye is a combination of small molecules called aromatic compounds, such as p-phenylenediamine (PPD) and p-toluene diamine (PTD). These compounds are able to penetrate into hair shafts and bind with proteins, which results in a change in hair color. The specific combination and concentration of these aromatic compounds will determine the shade and intensity of the hair dye.