[numpad0]

Looking at the author's explanation for HSV and HSL, it sounds like they are designed for hypothetical programmable wavelength lights and paints. Hue would be wavelength, Saturation is either output filter bandwidth or conversion element efficiency, Value/Lightness is either output current or amount of ink.

RGB is likewise for fixed wavelength three-color lights/filters, and CMYK is for prints. I think it's the same situation as units of measurements in aviation[1] being all over the places; the measurements are tied to specific devices, principles and usages of them.

1: Altitude in feet measured by pressure altimeters, distances measured in nautical miles defined as one minute of latitude, fuel in pounds and dimensions in inches, but never altitudes in miles or distances in feet, except for runway lengths which is always feet or meters.

[p1mrx]

> Hue would be wavelength

This doesn't work, because "https://en.wikipedia.org/wiki/Magenta is an extra-spectral color, meaning that it is not a hue associated with monochromatic visible light."

[egypturnash]

HSV/L are conceptually close to the way artists have been thinking about color for centuries, since the days when everyone ground their own pigments.

Hue is the angle on the color wheel. Which somewhat translates to wavelength if you ignore the fact that we see chords of high blue + low red as the colors we give names like purple, indigo, violet, and magenta.

Saturation is how intense the color is. Lower the saturation and it turns grey, or pastel. We have a few special names here; "pink" is a low-saturation red, for instance.

Value/lightness how dark/light a color is. Lower the value on that "pink" and you might get something you'd label "brick red": it's darker, it's still definitely reddish, but it's not the most intense red you can get while still being kinda dark.

Saturation collapses as you go to the extremes of value/lightness, it's just pitch black at one end and pure white light at the other.

[arthur2e5]

The whole HSL and HSV business has never been about hypothetical light sources. HSL and HSV are created from monitor CRT RGB using piecewise functions for the hue. No colorimetric considerations are given at all: it’s all about how to mix an algebraic mean.