[css-color] string args for named color profiles

[svgeesus]

https://drafts.csswg.org/css-color/#color-function

Need to add choice of quoted string or number+, to allow for named color profiles.

[svgeesus]

Spec syntax already has this:
color() = color( <ident> , [ <number>+ | <string> ] , <alpha-value>? , <color>? )