About pink/magenta stain I think that it is a dye that can be seen in every in color film and some BW film with color derived chemestry (e.g T-max).
Most color labs use a short or no wash going directly on stab bath, a regular procedure that can be find in kodak datasheet.
In home processing, where you can "waste" time, color films can be thoroughly washed. After the first 30" water rinse after fixer, water came off with a strong magenta color; if you wash your films for 10-15 minutes with a series of 30-60-120 seconds rinses untill wash water are clear the magenta cast on film disappear. I saw this with slide films (and may be that velvia magenta cast was due to washing too short?), color negative films (thorougly washed color negs have a less dense orange mask), with chromogenic BW films and of course with maskless color negs like Phoenix.
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