Barium Nitrate Powder
[Ba(NO3)2] White powder
Barium nitrate is an oxidizer used to make green color in fireworks stars, fountains, etc. It's also used in sparklers, flash powder, and other applications.
You cannot interchange these with barium nitrate, but other green coloring agents are the oxidizer barium chlorate and the salt--barium chloride. Boric acid is used in some liquid fire formulas.
You can make green stars with barium nitrate using this formula: Emerald Green Illuminating Star.