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TODO: copy over from the colors html

ISCC-NBS Color Centroid Table

The following colors are based on the ISCC-NBS color system, a color naming system devised by the National Bureau of Standards based on the Munsell color system..

This color system actually defines “blocks” of colors, and these are the centroids.

For ease of reading, I call yellow-green ‘chartreuse’ to distinguish from yellowish-green. Also, I combine the modifiers of ‘light -ish gray’ and ‘pale’.

Motivation and explanation

Colors are hard. Some colors we see can’t be shown on a screen. Some colors on a screen can’t be printed. RGB values don’t cleanly map to human perception because our eyes are most sensitive to green light.

While looking up visualizations of XKCD’s color survey data, I found Aubrey Jaffer’s site, which contains comparisons of several color name dictionaries.

According to the author, most online color dictionaries don’t evenly cover the range of human perception, and include a number of colors which can’t be reproduced in print. They provide several alternate color dictionaries limited to the print gamut, including a cleaned-up version of the ISCC-NBS system with html-style color codes.

I was intrigued by the system, but unsatisfied with it’s presentation.

  • This Catalog organizes colors nicely, but in pdf form.
  • This and this text file clearly is easy to access and copy from, but doesn’t preview the color.
  • This linked comparison table presents all the info and colors I want, but puts this in a verbose list that requires lots of scrolling.
  • This list has a similar problem.

In my table above,

  • I organize the blocks in a grid by category and modifier
  • I only use one value for each block, based on the color centroids from this source. (Do note that each color name refers to a range of colors. These all count as vivid blue.)
  • I include plaintext html codes for easy copypasting into Gimp or Inkscape.

More details about the history of ISCC NBS color can be found here.

Changes from the linked color dictionary

  • Having both yellowishgreen and yellowgreen is confusing. I’ve relabelled yellowgreen as chartreuse.
  • merged all lightgrayish- labels into pale labels.
  • Several of the entries were based on guesses by the author. I disagree with some of these guesses, and have tried to improve upon them by interpolating similarly named colors in LCh color space.
    • vivid blue
      • was 00A1C2
      • changed to 0072ff(interpolation) or maybe less chroma 3b74ea for print friendliness
      • changed to 6375ba
      • changed to 367cc7
    • deep greenish blue
      • Was 2E8495
      • Changed to 00444f or 004652
    • vivid purplishblue
      • was 30267a
      • now 736ad0, made brighter with same hue and relative chroma
  • relabelled some nuetral colors to make names more consistent in terms of relative luminosity
    • light…ishgrays have a relative luminosity of approx 75%
    • pinkishgray -> lightpinkishgray
    • yellowishgray -> lightyellowishgray
    • brownishgray -> darkbrownishgray
    • lightbrownishgray -> brownishgray
    • olivegray -> darkolivegray
    • lightolivegray -> olivegray

License info for the color dictionary used:

! Copyright © 2003 Voluntocracy.  Permission is granted to copy and
! distribute modified or unmodified versions of this color dictionary
! provided the copyright notice and this permission notice are preserved
! on all copies and the entire such work is distributed under the terms
! of a permission notice identical to this one.