What is the primary function of iron oxides in cosmetic products?

To provide color and pigment

Iron oxides serve as the fundamental coloring agents in various cosmetics, including foundations and eyeshadows. These compounds are metallic elements typically found in oxide forms rather than pure elemental forms to ensure safety upon skin contact. By utilizing these minerals, manufacturers are able to achieve a wide spectrum of hues ranging from deep browns and reds to yellows, effectively saturating the product with the desired color.