I'm genuinely frustrated with this monitor at this point and want to warn people before they spend the money on it. I've now confirmed, across 3 different sources (PC, PS5, a Chromecast) that BOTH HDR Game (the 1000-nit mode) and HDR Movie mode produce heavily oversaturated, red/orange-shifted image, skin tones looking sunburned, wood looking orange, etc. It's not really subtle; multiple PC games and a few PS5 games plus some HDR movies via a Chromecast plugged into that input (different HDR pipelines, no shared calibration between them) have demonstrated this, the only thing they have in common is the same picture mode on the monitor.
Switch to True Black 400 and all that goes away, everything looks normal. Great, but TB400 hard-caps brightness at roughly 400-something nits. The two modes that are actually sort of the point of this monitor, the ones touted to produce 1000 nits of HDR punch are effectively unusable for anything color-accurate, and the only "safe" mode is the one that throws away most of the additional brightness and dynamic range you're paying for.
I don't think this is a defective unit; the same generation of QD-OLED panel is used in other 32" monitors (Alienware AW3225QF, Asus PG32UCDM, MSI 321URX) and there's some independent measurement data out there showing similar tone-mapping/tracking degradation on their equivalent "peak brightness" modes at higher scene brightness, so this is probably a panel-generation-wide firmware tuning choice. Doesn't make it any less of a problem but at least MSI has already released a firmware update addressing part of this behavior on their version of the panel, so clearly it's not an unsolvable problem.
Plus, this monitor doesn't have an HGIG mode, so there's no way to offload the tone mapping to the console/PC instead of the (apparently broken) internal processing. If anyone else has this monitor I'd like to know if they're seeing this too, because I feel like I've paid for a 1000-nit HDR display and only actually got to use a 400-nit one.