Organic colors (lakes and dyes) are synthetic, chemically very complex molecules and are divided into various groups including indigoids, xanthenes, azos, nitros and others. As compared to inorganic colors, organic colors are available in a larger variety of shades. Liquid colors are colors that have been dispersed in castor oil. Liquid colors are very practical and easy to use as they can be easily blended with other oil-dispersed colors. Liquid colors are particularly useful for making lipsticks, lip gloss, and blush. Since certain organic colors can be irritant to mucous membranes, all organic pigments must be approved and certified by the FDA.