Kodachrome has a built in yellow colloidal silver filter
Wasn't there a built-in yellow filter behind the blue sensitive emulsion layer in Kodachrome? It was made out of colloidal silver, IIRC, which a a form of silver that is naturally yellow in color. Thus it would serve to filter out the blue photons from the red and green sensitive layers (since these layers are also sensitive to blue light).
Originally Posted by dmschnute
Apparently this colloidal silver layer is made out of metallic silver particles and not silver halide particles, else it would be fixed out in the hypo fixing bath. Since in normally processed Kodachrome the silver metal is bleached to ag+1 and then fixed, the colloidal silver is transformed into silver ions which will dissolve in hypo.
However, being colloidal, the silver metal particles might be very much smaller than typical grains and might be more susceptible to bleaching than the rest of the emulsion. Could a brief bleach selectively affect the colloidal silver only and not the image grains? Allowing just the yellow colloidal silver layer to be removed? Just asking if anyone knows.