Oxides and pigments are made from natural and synthetic elements. In cosmetics and personal care products, Iron Oxides are used in the formulation of a wide variety of product types, including makeup and skin care preparations. Iron Oxides are naturally occuring mineral deposits. These compounds are used as pigments in a variety of applications. Iron Oxides used in cosmetic and personal care products. These colors are an excellent choice for CP soap and MP soap, but are not limited to that use, let your imagination run wild.