Red 40 Red 40 is a dye commonly used as food coloring in todayâ€™s foods. The proper chemical name is actually 6-hydroxy-5-[(2-methoxy-5-methyl-4-sulfophenyl)azo]-2-naphthalenesulfonic acid, but also known as â€œazoâ€� dye. By itself Red 40 has an orangish-red color and found in cherry and strawberry flavored foods. Orange foods are typically dyed with Yellow 6. See Yellow 6. All dyes are considered additives by the FDA through the Federal Food, Drug, and Cosmetic Act (FD&C Act) since it is not used for the purpose of consumption, but to improve the appearance of the product. For example, chocolate pudding would be slightly greener without the use of red dye. Not just limited to foods, Red 40 is also used for coloring in cosmetics and sold as powders or liquids. "Electronic Code of Federal Regulations." GPO Home Page. Title 21. Part 74, 12 May 2011. Web. 16 May 2011. . FD&C Red Dye #40 Information, Education and Discussion. Web. 16 May 2011. .