Artificial red colourants certified under the US Food, Drug and Cosmetic (FD&C) Act. Currently, two reds are permitted for US food use: FDC Red 40 (Allura Red AC) and FDC Red 3 (erythrosine). Permitted uses and limits are set for each certified colour. Allura Red AC dominates red confectionery, beverages and cereals for its bright, stable hue, while erythrosine’s use has narrowed under safety review. Both must be declared by name or number, and the EU’s Southampton-study warning labels apply to Allura Red among five colours linked to hyperactivity in children.