Wangkou fireworks

Produced in Xinji, Hebei Province. The color is caused by various metal salts (collectively referred to as dyes) mixed into the gun powder. When the dye is potassium salt, the fireworks appear purple; When it is sodium salt, it appears yellow; When it is strontium salt, it appears red; When it is barium salt, it appears green; It is blue when it is copper salt. If it contains light metals such as magnesium and aluminum, it will glow after burning at high temperature. And some non-combustible characteristics will form many smoke screens. When fireworks shoot into the sky, these salts react chemically with oxygen in the air, thus producing dazzling colorful colors.
Reprinted with attribution： https://cnlocality.com/(Chinese Specialty Products)