Play-of-colour as real diffraction: silica domains each returning one colour set by their sphere size, flashing on and off as the Bragg angle is met, with hard edges between plates the way an actual stone fires.
Drawn with: a WebGL2 shader.
Reacts to and looks like: gpu, webgl2 and audio-reactive.
Family: Visualiser.
Runs in your browser. The preview above is the same program the renderer uses.