[csswg-drafts] [css-color-4] (ok)lch implementations break the entire purpose for authors (#9449)

mirisuzanne has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-color-4] (ok)lch implementations break the entire purpose for authors ==
This is not an issue in the css-color-4 spec, but in all the implementations. While issues have been filed on the individual bug trackers, I wanted to raise the issue with the CSSWG since it seems like this was an intentional decision agreed to by the browser vendors.

Here are the individual bug reports:

- https://bugs.webkit.org/show_bug.cgi?id=255939
- https://bugzilla.mozilla.org/show_bug.cgi?id=1847421
- https://bugs.chromium.org/p/chromium/issues/detail?id=1440069&q=lch&can=2

And, as I understand, the decision was made in these CSSWG issues:

- https://github.com/w3c/csswg-drafts/issues/7610
- https://github.com/w3c/csswg-drafts/issues/7653

I'm opening a separate issue because I don't have strong feelings about all the details of a gamut mapping algorithm, but I'm pretty frustrated about the state of what browsers shipped here, and I think we need to do something to fix it asap. From an authoring perspective it's entirely unusable, and _ it breaks the fundamental promise of the format_: providing perceptually-uniform lightness.

- Here's a [codepen demo](https://codepen.io/miriamsuzanne/pen/BavZLNG) showing two colors with the same hue and lightness values, but vastly different perceptual lightness in the results.
- Here's a [tool for comparing gamut-mapping options](https://svgees.us/Color/ok-clip-lch-explorer.html) - set the lightness low (eg 0.25) and clip gives colors which are over-saturated/too light, set the lightness high (eg .85) and clip gives over-saturated and too dark.

This is the format that authors were most excited about, and it doesn't do what we told them it does. I really wish this feature hadn't shipped at all, since it clearly wasn't ready to ship. Adding agenda+ because I think this deserves more eyes on it, and more urgency in fixing it.

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/9449 using your GitHub account


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Received on Monday, 9 October 2023 19:00:04 UTC