The figure shows the colour map with low gradient ripples to indicate how it represents low-contrast regions in different locations of the colorbar, and a plot of the lightness difference, dE, indicating better perceptual-uniformity the flatter the curve.
A man with a conviction is a hard man to change. Tell him you disagree and he turns away. Show him facts or figures and he questions your sources. Appeal to logic and he fails to see your point. - Festinger 1956
An incomplete chronology
2020 Crameri, F., G.E. Shephard, P.J. Heron, “The misuse of colour in science communication”, Nature Communications, 11, 5444.
2017 Crameri, F., “The Rainbow colour map (repeatedly) considered harmful”, EGU GD blog.
2007 D. Borland and R.M. Tailor, “Rainbow Color Map (still) considered harmful,” IEEE Computer Society, vol. 07, 2007, p. 14-17.
2004 A. Light and P.J. Bartlein, “The End of the Rainbow? Color Schemes for Improved Data Graphics,” EOS Trans. Amer. Geophysical Union, vol. 85, no. 40, 2004, p. 385.
2004 C. Ware, Information Visualization: Perception for Design, 2nd ed., Morgan Kaufmann, 2004.
1998 B.E. Rogowitz and L.A. Treinish, “Data Visualization: The End of the Rainbow,” IEEE Spectrum, vol. 35, no. 12, 1998, pp. 52-59.