Hacker News Reader

Comment by Daub | Hacker News Reader

Hue is a surprisingly non-linear phenomenon.

The maximum saturation occurs at a different lightness value for each hue. Blue is most saturated when it is dark, and yellow is most saturated when it is light. It is for this reason that some people erroneously describe yellow as being a bright Colour.

To added even further perversity to the mix, there are fewer (perceivable) yellows than there are perceivable greens. Relative perceivable values of hues are readily apparent in the Munsell Colour space, shown here:

https://i.pinimg.com/originals/4b/43/84/4b438408b064533fc862...

Moral of the story? Colour is difficult.

View on HN

I was surprised that saturation wasn't mentioned at all in the article.

I too am a bit surprised. I could never address a problem of color perception without cycling through the relevant HSL values.

As a designer, colour models like RGB, Lab, CMTK and hex are of instruments of application. All well and good, but if you want a colour model that is suitable for thinking about colors with, then HSL (or HSV) is the only option.

As an exercise, I get my students to define the difference between color pairs using HSL. Even high school students can do it. Try that with RGB!

i'm primarily using hsl now (though have long used rgb before that), but have experimented with oklch because of the promise of an even more uniform perceptual color space. the big problem i found with lch & oklch are discontinuities in the valid ranges of lightness and chroma, which functionally dependent on the hue value (from my perspective that hue is the independent variable to set first).

color spaces definitely defy straightforward intuition about them.

I agree that as a practical space HSL is limited. Indeed, HSL was supported in the first two versions of Photoshop, but was abandoned as being too inconsistent. A conversion to and from HSL resulted in a mess. However Photoshop, like all design apps, features an HSL colour picker.

Thanks for introducing me to OKLAB.

> From my perspective that hue is the independent variable to set first

Agreed.

> Color spaces definitely defy straightforward intuition about them.

You are aware of Kuehnis book "Color space and its divisions."? It is a great read on this fascinating subject.

yah, the other neat thing about lab/lch/oklab/oklch is that they're theoretically unbounded, so as our screens get better at reproducing more of the visible spectrum, you just use more extant values rather than switching color spaces (unlike rgb & hsl).

i haven't read that book, but i'll have to check it out!

Reply on news.ycombinator.com