[css-fonts] [palettes] font-palette cannot be expanded in the future #6633
Description
The grammar for font-palette is none | normal | light | dark | <palette-identifier>, and <palette-identifier> is a <custom-ident>. This means that, if the WG wants to add a new value foo to the font-palette property, it could conflict with a user-created foo palette-identifier.
I suppose the natural way to solve this is to say that if there's an @font-palette-values rule with the same name as one of the named values to the font-palette property, then the @font-palette-values rule wins. (This is how @font-face names work if there's an installed font with the same name.)
Another alternative solution would be to use a function, like:
font-palette: none | normal | light | dark | custom-palette(<palette-identifier>)