Red 21 Good Colouring Agent/Pigment No known benefits Red 21 at a glance Synthetic pigment Ruled safe as used in cosmetics and food products Also known as D&C Red No. 21 Red 21 description Red 21 is a synthetic pigment used to add colour to makeup, skin care and food products. The United States Food and Drug Administration has ruled it safe as it is used in these applications. It is also known as D&C Red No. 21, with the “D&C” designation meaning it is approved for use in drugs and cosmetics. Related ingredients: Red 27 Lake Red 28 Red 33 Red 6 Lake Red 7 Lake D&C Colors