The FDX crash was based on bad science...The 2 other crew members both had the same view of the runway, and both had normal color vision. Neither of them noticed a thing. The problem there was fatigue, not color vision.
I think you mean the FDX accident investigation was based on bad science.
The CRASH was based on loss of SA by the crew for one.
You are correct about the all members of the crew not recounting anything about all red PAPIs. Some even make mention of the FO's misidentification of another flashing white light as the airport beacon as further evidence of his deficiency, yet makes no mention of another FDX CA who regularly flew into the airport mentioning that many make the same mistake.
Oh - and I also remember reading something about condensation on the PAPI lights that can make the red look pink (closer to the whites), and same thing with certain transition angles... Something to consider.
Yes - many P139 airports now have VGSI systems on 24/7 I believe, but not ALL airports use them - - something to remember if you are the pilot flying into such an airport. I'm not sure what you mean about certain transition angles?
USMCFLYR