An audiogram is not a chart style, it is a form. Frequency in hertz runs across the top on octave steps, hearing level in decibels runs downward on the side, and both ears are plotted on the same grid: right ear a red O, left ear a blue X, bone conduction in brackets that face the reader like ears.

The discipline worth stealing is the redundancy. Shape carries the meaning; colour only confirms it. The whole form still reads after a bad photocopy, which is why nothing here is filled, glossy, or dependent on hue alone.