So everybody knows about the American Electric stuff and how it would turn purple. But I recall that being an issue well before American American Electric Autobahns did it.  Those eBay LED floodlights that used to be very popular, parts of the diodes would would flake off and they would emit a purple color.  Or a lot of Walmart stores at 1 point over the produce section had 8' indirect linear LED lights, I think they were made by either GE or Cree if I remember correctly and those would either shift to green or purple. Some of the early 3/5 mm LEDs in hand held Flash lights would also slowly shift to purple, but not as extreme as the other stuff memtioned.  The city of Ann Arbor Michigan on their own poles also installed these LED lights which I have no clue what they are,those things also would shift to purple before the AEL ones.

For me I'm pretty sure it was at Winn Dixie. They had LED spotlights that they installed in a remodel in 2008, in the produce and bakery departments and also around the seafood and meat depts, and those all did seem to shift to a weird blue/green color after a few years. I think they all got replaced late last year when they did another remodel, so I can't verify at this point.

Definitely was one of the first LED installs I ever saw.

York had some ATBX lights that looked like they were in the early stages of shifting purple but it might've been because of the black finish. Maybe the entire park and ride with dayburning purple ATB0s in Tyngsboro MA. That was more recent so I'm not sure, Maybe I've seen some before.

I don't think I've seen one in person yet. American Electric LED luminaires aren't that common in my immediate area either.