Synthetic food pigments are made from aniline dyes separated from coal tar, so they are also called coal tar pigments or aniline pigments, such as synthetic amaranth, carmine and lemon yellow. These synthetic pigments are harmful to human body, because it is easy to induce poisoning, diarrhea and even cancer.

Article 143 of China's Criminal Law explains: whoever produces or sells food that does not meet the hygiene standards enough to cause serious food poisoning accidents or other serious food-borne diseases shall be sentenced to fixed-term imprisonment of not more than three years or criminal detention, and shall also or only be fined not less than 50% but not more than two times the sales amount. Whoever causes serious harm to human health shall be sentenced to fixed-term imprisonment of not less than three years but not more than seven years, and shall also be fined not less than 50% but not more than two times the sales amount. If the consequences are especially serious, he shall be sentenced to fixed-term imprisonment of not less than seven years or life imprisonment, and shall also be fined not less than 50% but not more than two times the sales amount or his property shall be confiscated.

Pigments can be divided into natural and synthetic. Natural edible pigments are pigments extracted directly from animal and plant tissues, which are generally harmless to human body, such as red rice, chlorophyll, curcumin, carotene, amaranth and sugar color, and so on.