WillLem: I think it's still a good test to see what happens on your Mac, even though the Macs of naymapl, cameo69, and Dominator_101 sound newer than yours (naymapl's M1 should be from 2020 and newer). Reason: Most likely, it's an Allegro bug. I already know that the bug affects both Intel and ARM Macs, and I hope that the bug doesn't depend too much on OS version. In particular, Dominator had no problems in 2021, and then in 2023, things were pink.
Mac build instructions for Lix, let me know if you run into problems, or if you want to do it on Mumble.
If you see the pink, that would be ideal, and we can continue to remote-troubleshoot.
If you don't see the pink, it'll be nice, but it'll be a weak result. Anything might have circumvented the bug then: Your Mac can be too old, current Allegro can have a fix, or Lix's custom recoloring function can have fixed it.
-- Simon