The United States FDA allows only 4 red and yellow artificial food dyes, which are used to color Tic Tacs and other foods. All four are linked to health risks and all four are banned in other countries.
Why gold: because gold is flexible enough, it is able to hold up very well to the force of biting and chewing, meaning it does not crack or chip under pressure. Gold is also highly resistant to food acids, oral bacteria, and corrosion, so it's one of the most long-lasting methods