Prior to the change to ASA25 for Kodachrome, it was known as Kodachrome II with an ASA of 10 in the 35 mm size. The original Kodachrome II was lacquer dipped so that the image would not be contaminated with fingerprints. There was also a Kodachrome X which became Kodachrome 64 (ASA64) for the same reason. The K25 vs. the K64 did have a slightly different color balance. Kodak eliminated the lacquer and renamed both films. Kodak later made process changes to go from inorganic to organic dyes (biodegradable) and the long term of the biodegradable dyes is less but probably still acceptable. When Kodak launched "restraint of trade" suit against Japan, the Japanese testified that the reason Kodachrome sales were almost non existent in Japan vs. Fuji was that the Kodachrome did not render skin tones correctly. Kodak made another process change to correct this, and it was not publicly announced in the USA, and only became known when the details of the lawsuit became available, I used Kodachrome almost exclusively when the ASA was increased until I could no longer find a lab that would develop the film. (I actually used the Kodachrome Professional that was "aged" to be optimum, and had to be kept refrigerated until it was used.) I still miss it, although my scanning experience has shown that a higher quality digital camera and lens, with careful attention to depth of field and f stop is every bit as good in terms of image sharpness, although most digital cameras do not have the dynamic range that film can produce.
having said all that, the photographer makes the image, not the camera or the film (or sensor).
