As the flame reaches these spots, it briefly changes colors. They had to invent an algorithm to convert different color patterns to letters and numbers. It’s sort of like an ASCII table for fire.

Flame colors span a spectrum that tells a tale as old as fire itself. Many people wonder what color is the hottest flame; more than a testament to the natural fascination with fire's beauty, this ...

Flames make electrons absorb energy, jump to a higher orbit, and then come crashing down, emitting photons of light. Burning Li 2 CO 3 creates flames at a wavelength that we perceive as an exotic red.