Wrote this to Leica forum (regarding Leica Ultravid), but maybe this is the right place.
After cleaning the pupil lens very gently (wiping dirt, using an optical chamois cloth and breath moisture), some local changes of the coating reflection colors (blue-red-green) can be noticed when you look carefully (and closely) for the reflections against artificial light source. Don't they have any optical/performances meaning at all (is it just cosmetics), or should the lens be cleaned further to eliminate them and have even color reflection?
Thanks in advance
I believe there were several answers to your query in the Leica forum. You will probably find them helpful. I wouldn't worry about the lens reflections. There is a detailed thread here on how to clean binocular lenses.
http://www.birdforum.net/showthread.php?t=30927
Cordially,
Bob