/*
  cpt-city: ds9/rainbow (cpt)

  The palettes used in the DS9 astronomical data visualization tool
  by William Joye of the Smithsonian Astrophysical Observatory

  author: William Joye
  copyright: GPLv2
  year: 2010
  url: https://phillips.shef.ac.uk/pub/cpt-city/ds9
*/
linear-gradient(
  0deg,
  rgb(255,   0, 255)   0.000%,
  rgb(  0,   0, 255)  20.000%,
  rgb(  0, 255, 255)  40.000%,
  rgb(  0, 255,   0)  60.000%,
  rgb(255, 255,   0)  80.000%,
  rgb(255,   0,   0) 100.000%
);