FD&C or D&C.
Artificial colors are made from petroleum and coal tar, and are believed to be cancer-causing agents. They may penetrate the skin, can cause allergies, and are irritants to the skin and eyes. They are found on labels as "FD&C" or "D&C" and followed by a color and a number. Yellow, amber, green, or blue products are dyed with synthetic colors, and should be avoided.