Leica M Typ 240 and a Right Side Magenta Color Cast
In Guide to Leica is published a discussion of the right-side magenta color cast issue that I experienced with the Leica 24mm f/3.8 Elmar-M ASPH and the Leica 21mm f/3.4 Super-Elmar-M ASPH.
I now have an explanation which I had overlooked before, though it applies only to the 24/3.8 in this particular case. And while it does not explain everything, it suggests one sanity check that Leica M users might want to follow, because it is easy to miss (camera provides no warning).