For the headline, "What Are FD&C Dyes ..." I was disappointed to see nothing about what FD&C dyes are (as opposed to a regular dye which I assumed is something

For the headline, "What Are FD&C Dyes ..." I was disappointed to see nothing about what FD&C dyes are (as opposed to a regular dye which I assumed is something like "a chemical that exhibits coloring power when dissolved").