Colorants are a major component of color cosmetics. Most cosmetics contain oils, surfactants, water, fragrances and other additives, which react with colorants to cause bleeding, condensation and stratification.

Colorants used in cosmetics are not only required to have good solvent resistance and good dispersion properties, but also to be selected through formulation and use tests to have no effect on fragrances, oils and skin secretions (such as sweat and fats). Otherwise, they will fade during storage and change color after use on the skin.

The pigments used in brightly colored cosmetics such as lipsticks and eye shadows are not only required to have bright colors, but also to have good coloring power, hiding power and water resistance. If such products have poor water resistance, they will shift in color; if the colorants have poor oil resistance, they will gradually change color. Therefore, it is necessary to use colorants that are stable to heat and pH changes, have fine and uniform particles, low water content and good light resistance.

1. Dyes

Colorants that can be dissolved in the medium used. It can be dissolved in a specified solvent and, with the help of the solvent as a medium, can color the dyed object. According to its solubility, it can be divided into water-soluble dyes and oil-soluble dyes.

2. Pigments

Colorants that are insoluble in the medium used. They are insoluble in the specified solvent and have good hiding power, and can color other substances. The commonly used color lakes and pearlescent pigments in cosmetics are both pigments.

3. Color lakes

Color lakes refer to a colorant made by adsorbing water-soluble dyes on insoluble carriers. They are insoluble in ordinary solvents and have high dispersibility. Pearlescent pigments refer to pigments composed of several metal oxides or thin layers of dyes coated with mica.

Color lakes are water-insoluble pigments generated by the reaction of water-soluble dyes (such as acid dyes, direct dyes, basic dyes, etc.) with precipitants. They have brighter colors, more complete color spectra, lower production costs, and higher light fastness than the original water-soluble dyes. Precipitants are mainly inorganic salts, acids, carriers, etc. Carrier precipitation is the process of depositing water-soluble dyes on the surface of carriers such as aluminum hydroxide and sulfuric acid to form water-insoluble lakes, such as acid golden lake (C.I. Pigment Orange 17) and light-fast lake blue lake (C.1. Pigment Blue 17).