NCS

[dy]

Seems that NCS will also require a sort of empirical/nn-calculated formula.
Because it is just a collection of colors
http://www.ncscolour.com/en/natural-colour-system/logic-behind-the-system/detailed-logic-behind-the-system/

[olehmelnyk]

Updated link http://ncscolour.com/about-us/how-the-ncs-system-works/

What if we just hardcode all the values? At least colors that start with S which means "standardized" should be hardcoded somehow.
All color samples (official site) http://ncscolour.com/product-category/shop/colour-samples/

Here's how to search for color http://ncscolour.com/product-category/shop/colour-samples/?s=1010-Y90R where the s= param is a color name

or here's a list of CMYK/RGB/HEX equivalents https://colorscheme.ru/ncs-colors.html

[olehmelnyk]

These page contain NCS conversion functions
http://jsfiddle.net/jdias/b3hEa/ -- NCS to HSV / RGB / HEX - not sure if this algorithm can be reverted for backward conversion

Another example of ncs to rgb and hex
https://github.com/m90/ncs-color

We also will need a json/csv/etc library of existing colors with names to check if this color is from the library and can be reproduced in print - well, this is what I can provide (if needed) - just let me know the preferred format... The same thing goes for HKS, TOYO, PANTONE, RAL, British Standard Colour, US Federal Standard 595, and other color libs that have names, that can't be generated by formula and must be stored somewhere... so we should create a standardized template/algo for such cases

[akrizs]

Anyone ever figure out the formula to convert rgb/hex/hsl/b to ncs?