Perceptual thresholds: Music inspired Newton's rainbow

Journal name:
Date published:
Published online

Isaac Newton was among the great scientists who took inspiration from music (see Nature 519, 262; 2015). In fact, music drove him to add two new colours to the rainbow.

The medieval rainbow had just five colours: red, yellow, green, blue and violet. Newton added two more — orange and indigo — so that the colours would be “divided after the manner of a Musical Chord” (I. Newton in Opticks 4th edn, 127 (William Innys, 1730); see also K. McLaren Color Res. Application 10, 225229; 1985).

On a seemingly unrelated note, Ed Hawkins and colleagues make a plea to scrap rainbow colour scales in scientific graphics (Nature 519, 291; 2015). They warn that these palettes can “introduce false perceptual thresholds in the data”.

It was Newton's perception that first introduced new colour thresholds, although these were subjective rather than false. It gives the lie to the old saying that artists see what they believe, but scientists believe what they see.

Author information


  1. University of Bristol, UK.

    • Len Fisher

Corresponding author

Correspondence to:

Author details

Additional data