Is it true that using a gold o platinum toner after fixation allows greater retention of the native color of the kallitype (which, of course, varies with the developer used)?
Any experience?
No, that is not true. In toning with gold, palladium or platinum the image will assume a color consistent with the color of the more noble metal, regardless of the native color of the kallitype, which of course can vary a lot depending on developer as you correctly point out.
Is it true that using a gold o platinum toner after fixation allows greater retention of the native color of the kallitype (which, of course, varies with the developer used)?
Any experience?
I believe that what Ed says is that if you tone *after* fixing there will be less color change than if you tone before fixing. That is correct, but most people appear to prefer to tone before fixing to avoid bleaching of the image in the fixer.