[csswg-drafts] [css-color-5] Please consider CIE Luv & CIE LCHuv (#13287)

mm2t has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-color-5] Please consider CIE Luv & CIE LCHuv ==
CIE Lab and CIE Luv were both standardized in 1976 by CIE as perceptually uniform color models (unlike CIE XYZ), encompassing all perceivable colors.

CIE recommended using CIE Lab for characterization of reflective surfaces and dyes (think print and product design), and using CIE Luv for displays and emissive surfaces (like VDUs and projectors).

Because color models like HSL and HSV simply transform RGB within its host color space (typically this was sRGB), they were not really perceptually uniform, but a practical 'good enough' utility more intuitive than the light color mixing RGB model.

It made sense for software like Photoshop to provide the more accurate and display-independent CIE Lab model for color specification, as typically, the output is _printed_.

<div align="center"><img width="50%" height="50%" alt="CIE Lab used in Photoshop color picking" src="https://github.com/user-attachments/assets/b42e0c7d-bf7f-469b-afe1-3036da7c03da" /></div>

It also made perfect sense for software like DaVinci Resolve to provide CIE Luv (and not CIE Lab) for color analysis, since the target output is obviously displays and projectors.

<div align="center"><img width="50%" height="50%" alt="CIE Luv used in DaVinci Resolve chromaticity scope" src="https://github.com/user-attachments/assets/b2fec48a-08f7-4b13-a429-c16bfd84e966" /></div>

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Why then, does CSS Color not offer a CIE Luv option to specify color? This is despite the fact that most web browsing and web apps are displayed on emissive displays like smartphones and computer monitors?

Furthermore, as far as I understand, the transformation to CIE Luv values is not really difficult, if not simpler than CIE Lab.

Hence, I would like to suggest to the CSS Color Working Group to consider including CIE Luv as a color value option.

<hr>

There are also intuitive color specification models based on CIE Luv. The **CIE LCHuv** color model is analogous to the CIE LCHab (derived from CIE Lab), which is already included in the CSS Color 5 WD as ["CIE LCH"](https://github.com/w3c/csswg-drafts/issues/13286) along with CIE Lab.

Also there is **HSLuv** [[1]](https://www.hsluv.org/comparison/)[[2]](https://www.hsluv.org/index.html) which further transforms LCHuv to the familiar HSL model. Though I don't think this would be accepted, [given that Okhsl already was not](https://github.com/w3c/csswg-drafts/issues/8659). However, I wanted to mention it for completeness.

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Thank you for your work and for the effort to include device-independent color specification.

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/13287 using your GitHub account


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Received on Friday, 2 January 2026 14:42:58 UTC