The vivid colors come from different metal ions. As the firework explodes, electrons in these atoms are excited to higher energy levels. When they return to their ground state, they emit light at specific wavelengths, producing characteristic colors:

• Strontium salts → Red

• Barium salts → Green

• Copper salts → Blue

• Sodium salts → Yellow

The sound and timing are controlled by chemical composition and physical design. Engineers must calculate reaction rates and fuse lengths precisely, making fireworks both a science and an art.