Amaranth color production

Many consumers view the color of lipstick as the most important characteristic of this product. The colors and dyes of lipsticks are generally regulated within the United States and include many water-insoluble (oil-soluble) products, such as brilliant blue, erythrosine, amaranth, rhodamine, tartrazine, dibromofluorescein, and tetrabromofluorescein (bluish-red com-pound). The dyes must be water insoluble otherwise, the color would quickly fade or be removed in a short time by the consumer through the movement of the saliva-soaked tongue across the lips. Water-soluble dyes such as green or blue food dyes may be used to provide lipstick coloration, but they are usually first laked or combined with metal oxides such as aluminum hydroxide [A1(OH3)] to form an insoluble precipitate that is then suspended in the oil base of the lipstick. 

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