[csswg-drafts] [css-color] gray(<number>) or gray(<percent>)

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

== [css-color] gray(<number>) or gray(<percent>) ==
The [spec](https://drafts.csswg.org/css-color-4/#grays) defines 
`gray()` as taking a number argument, but the prose around it shows it
 being used with a percentage.

Please view or discuss this issue at 
https://github.com/w3c/csswg-drafts/issues/872 using your GitHub 
account