Allow defining cicp color states with an @-rule:
@cicp "jpeg" {
primaries: 1;
transfer: 13;
matrix: 6;
range: full;
}
And allow using them in color() like this:
color("jpeg" 50% 0.5 1 / 75%)
Note that custom color states use a string, unlike default color
states which use an ident.
Test included.