- From: Chris Lilley via GitHub <sysbot+gh@w3.org>
- Date: Wed, 16 Feb 2022 22:12:39 +0000
- To: public-css-archive@w3.org
Redirecting discussion back to original subject: > Right now the distinction between which color formats have a dedicated function and which ones are specified via color() is murky. The spec describes color() as "Profiled, Device-dependent Colors", but also includes [the XYZ spaces](https://drafts.csswg.org/css-color-4/#valdef-color-xyz) there. A little progress since the issue was first raised: 1. With the move of custom color spaces to CSS Color 5, the section is now entitled [10. Predefined Color Spaces](https://drafts.csswg.org/css-color-4/#predefined) which is not necessarily optimal, but is better 2. Again with that move, all the color spaces in that section are 3-component, rectilinear, [0,0,0] == black ones. (In CSS Color 4 that becomes _n_-dimensional but again with all zeroes == black). 3. CIE XYZ is, when you look at it carefully, a hyper-saturated primary RGB space. This is easier to see in an _x,y_ chromaticity diagram rather than a more modern _u,v_ one. Red (X) is at _x,y_=1,0; green(Y) is at _x,y_=1,0 while blue(Z) is at _x,y_=0.0 The other ones are opponent color spaces (neutral central axis with perceptual Lightness); `oklch` and 'lch` aim at being fully orthogonal (`oklch` is rather better at that, by design) while `oklab` and `lab` are sort of half-way houses, `a` and `b` don't mean that much in isolation. True, negating a value gets the opponent color, but they are much better expressed in polar form as orthogonal Chroma and Hue. -- GitHub Notification of comment by svgeesus Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/6741#issuecomment-1042361230 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Wednesday, 16 February 2022 22:12:41 UTC