Candy with moving colors, colorful drinks and Chinese and western cakes with all colors and flavors are very attractive to many people. Food and candy can be colorful because of the addition of pigments. Pigments are generally divided into natural and artificial. Natural pigments are non-toxic, and artificial pigments are extracted from coal tar. Although they are brightly colored and cheap, most of them are toxic and carcinogenic. At present, artificial pigments are widely used, and only four kinds are allowed to be used, namely amaranth, carmine, lemon yellow and indigo, and the dosage is also strictly limited, and it is only limited to candy, fruit wine, soda, drinks and cakes.

In order to make money, some food processing units and cold drink processing units add too much pigment to foods and drinks, which is euphemistically called bright color, fragrant, sweet and delicious. In fact, too much pigment is harmful to human body, and long-term consumption can indeed cause cancer. In particular, some people add non-edible pigments to foods and drinks, which is even more harmful to the human body.