This was the oldest Kodachrome from the most recently scanned box of my father’s slides. Shame about the focus/blur, but it is from March 1946, he’d just returned from WWII and the camera likely wasn’t the greatest, and the Kodachrome at the time was ASA 10 if I recall correctly. Colors don’t seem all that far removed from modern emulsions. Maybe even nicer
The Agfachrome slides stored in the same box from the early Fifties were completely gone, the Ektachrome ones from the Fifties were in poor shape as well.