- From: Chris Lilley <chris@w3.org>
- Date: Wed, 22 Jul 2015 11:56:51 +0200
- To: "Tab Atkins Jr." <jackalmage@gmail.com>, Nikita Vasilyev <me@elv1s.ru>
- CC: www-style list <www-style@w3.org>
Hello Tab, Monday, July 13, 2015, 10:16:51 PM, you wrote: > Amusingly, Mike Bostock has another page describing the HCL rainbow as > "ugly" <http://bl.ocks.org/mbostock/310c99e53880faec2434> ^_^ Not really seeing the relevance of that to this issue, which is about adding LCH (and of course Lab) to css4 color. LCH(ab) is simply the polar form of Lab: C = sqrt(a^2 + b^2) H = atan2(b, a) Frankly the main obstacle to my putting these in CSS color 4 - which I intend to do - is what would be a good syntactic form, how to do fallback, etc. SVG had these already, with an sRGB fallback. It was dropped from SVG2 because they would be better in CSS so they could be used for HTML/CSS as well. Having got such a space, *one* of the things one can then do with it is produce an even-perceptual-spacing color scale for scientific visualisation. Note the scientific - the point there is to avoid hiding or exaggerating small changes in the underlying visualized values. "Prettiness" is a non-goal in that situation - and if desired, with bright saturated non-evenly-spaced colors, its easy to do in RGB or HSL. > I am currently (slowly) working on turning the CubeHelix rainbow into > something usable as a CSS color system. It's intended to be the basis > of a new named color system, but it should be useful as an HCL-like > system as well, that's hopefully a bit more attractive. You would need to demonstrate perceptual uniformity for it to be useful as an LCH-like or Lab-like system. -- Best regards, Chris Lilley Technical Director, W3C Interaction Domain
Received on Wednesday, 22 July 2015 09:56:57 UTC