Erythrosine, also known as Red No. 3, is a cherry-pink synthetic dye primarily used in food, pharmaceuticals, and cosmetics. Its E number is E127. It's commonly used to add color to various products, including candies, popsicles, sauces, and medications. However, its use has declined in recent years due to concerns about its safety, particularly its potential carcinogenicity and other health risks. As a result, some regulatory bodies have restricted or banned its use in certain applications.