Are we getting mixed up between toners and dyes? They do different jobs, in different ways. A toner affects the silver metal (ie. 'dark' areas in a positive print) while a dye affects the baryta and paper base (ie. 'light' areas in a positive print, behind the silver image).
Wasn't there even a Kentmere paper manufactured with different coloured paper-base material? I seem to remember red and blue paper anyway, each with a silver image on top in the usual way.