Re: [csswg-drafts] [css-color-5] Colors where all channels (except) alpha have a value of `none` (#10203)

The CSS Working Group just [discussed](https://www.w3.org/2025/08/19-css-color-minutes.html#b50b) `[css-color-5] Colors where all channels (except) alpha have a value of none` 

<details><summary>The full IRC log of that discussion</summary>
lea: this is very related <br>
lea: to the previous resolution <br>
lea: we already have a resolution to extend analogous components to a set of components <br>
lea [w3c/csswg-drafts#10210](https://github.com/w3c/csswg-drafts/issues/10210) <br>
lea: we used to have the concept of analogous component when you are converting LAB to LCH <br>
L is analogous component in both, so we dont have to convert `none` to 0 <br>
lea: but if A and B both none, even if not individually analoguous, we now extend this for set <br>
lea: so they both stay none <br>
lea: what happen when you consider the empty set <br>
&lt;TabAtkins> lea: So if L in lch is analogous to L in lab, then ch (as a set) are analogous to ab (as a set) too <br>
lea: when empty set, all components are analoguous together. so we don't need to convert any of them to 0 regardless of the colorspace <br>
TabAtkins: yes we already resolved on that <br>
ChrisL: what about transparent ? <br>
ChrisL: we could add new keyword opaque for rgb(none none none 0%) <br>
ChrisL: new current is opaque, different from already existing transparent <br>
florian: until there is a demand for this keyword, maybe lets not do this <br>
Proposal: close, no change <br>
ChrisL: I agreed the keyword opaque could exist <br>
<lea> PROPOSED RESOLUTION: No new `opaque` keyword until motivated by author demand / use cases <br>
romain: this is not very different from transparent <br>
romain: but transparent already acts as being all none <br>
ChrisL: because we do everything in pre multipled, yes it acts the same <br>
romain: when a framework defines its color as a color-mix with a variable you can influence, there is no way to have the other side color <br>
TabAtkins: for this usecase why you wouldnt use the new alpha function ? <br>
romain: because you influence not just the alpha with color-mix <br>
romain: lets take it back to the issue to better describe it <br>
no resolution, we will take it back to the issue <br>
</details>

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Received on Tuesday, 19 August 2025 14:08:43 UTC