I've had that random red but only in the menu bar, open any window and it's gone. I've tried to screenshot it, but anything I do it disappears. It started in Sonoma. I don't believe it's a hardware issue at least in my case as I can't replicate it and it's only happened maybe 6 or 7 times and not in Sequoia.
1 kernel panic with Affinity Photo2.
2019 19,1 iMac, 64 GB of RAM, Radeon Pro 575X 4 GB, on an external 1TB Thunderbolt Drive, build 24A5320a,
Intel Macs as far as I know can't update to 15.1 yet.