The trick is "Sunset Yellow"

Hualian Supermarket has recently been exposed to a lean meat filling with a dye called “big red”, and “Sunset Yellow” is the main ingredient of this dye.

“Sunset Yellow” is a food additive approved for use in China. It is mainly used for the coloring of foods and medicines, and it can also be used to manufacture aluminum salt lake pigments. The use of "Sunset Yellow" is limited to foods such as cakes, fruit-flavored syrups, beverages, brewed liquors, jelly, puffed foods, etc., and all have corresponding maximum usage. The scope of use does not include raw, fresh, cooked meat products.