How are fireworks' colors and distinctive shapes attained?

I’m referring to the large fireworks that are launched into the sky at fireworks displays.

How do the manufacturers make each firework a particular color, and in some instances, cause it to explode in a particular pattern, like a heart or something? How is that achieved?

Colors have to do with the chemical composition of the explosive. Different things burn different colors. Copper burns green, for example.

I have seen a TV show on making them perhaps “How it is Made”. For the heart shaped display they actually pack the small color shells in a miniature heart form within the shell. A bursting charge is in the center. When it blows up the shells expand outwards but keep the general shape of a heart. Pretty simple.

Just for interest, some of the really spectacular displays are now performed by drones.

These Drone Light Shows Could Replace Fireworks - YouTube

Drone fireworks - Google Search


Here’s a handy guide for different elements making different colors: