Polyaspartic acid has the property of carboxyl group carrying negative charge, which allows it to form an adsorption layer on the surface of powder particles, thus producing an enhanced spatial site resistance effect and increasing the site resistance repulsion between particles. This property makes polyaspartic acid very effective when used as a dispersing colorant in color cosmetics formulations, which can evenly and effectively disperse pigments, especially inorganic pigments, and inhibit particle agglomeration, thus achieving uniform coloring and better coloration. In addition, because of its good dispersibility and high color mixing stability, it can be used in color cosmetics products such as eyeliner, mascara, foundation and nail polish. Using polyaspartic acid as a dispersing colorant not only improves the coloring effect of the products, but also makes the products more gentle an reduces the irritation to the skin.