[csswg-drafts] [css-color-4] `rgba()` is legacy so does not support `none`. Right? (#7900)

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

== [css-color-4] `rgba()` is legacy so does not support `none`. Right? ==
From [CSS Color 4](https://w3c.github.io/csswg-drafts/css-color-4/#rgb-functions):

> The [rgb()](https://w3c.github.io/csswg-drafts/css-color-4/#funcdef-rgb) function defines an sRGB color by specifying the red, green, and blue channels directly

> For legacy reasons, [rgb()](https://w3c.github.io/csswg-drafts/css-color-4/#funcdef-rgb) also supports a [legacy color syntax](https://w3c.github.io/csswg-drafts/css-color-4/#legacy-color-syntax) that separates all of its arguments with commas:

> Also, an rgba() [legacy color syntax](https://w3c.github.io/csswg-drafts/css-color-4/#legacy-color-syntax) also exists, with an identical grammar and behavior to [rgb()](https://w3c.github.io/csswg-drafts/css-color-4/#funcdef-rgb).

Now I guess there are two ways of reading this:

a) `rgba()` is a legacy only syntax, so `rgba(18% none 56% / 30%)` is invalid
b) `rgba()` has a modern syntax, which is not described explicitly but is "identical" except for using rgba, and a legacy syntax given below.

@tabatkins Which is it? 

I had assumed a). But WPT tests like [parsing/color-computed-rgb.html](https://github.com/web-platform-tests/wpt/blob/60c12a6237/css/css-color/parsing/color-computed-rgb.html) seem to assume b). [WPT results](https://wpt.fyi/results/css/css-color/parsing/color-computed-rgb.html?label=experimental&label=master&aligned) as do Chrome and Safari.

Either way the spec needs to clarify.

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/7900 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config

Received on Tuesday, 18 October 2022 17:20:20 UTC