HDR on PC Color Mapping Issue

I'm running Destiny 2 on Windows 10 (Creators Update but not the Fall creator's) with an nVidia card (900 series) and an LG C6P OLED TV, latest nVidia driver. Contrary to a bunch of people I can enable HDR mode just fine. However, I'm seeing really weird color mapping issues. It's blindingly obvious right at the start of the game/tutorial where you're standing in front of the burning tower. In SDR, the entire scene is a rich red with orange and white hues in the fire. In HDR, the entire scene becomes very much burnt or cadmium orange.

This isn't a color saturation problem either. I can use the color channel tool on the TV to look at the red/green/blue channels, and there's a ton more luminance in the green channel in HDR than there is in SDR, which I think is leading to the shift to orange. But it's not just this scene... throughout the tutorial there is no solid red hue anywhere, even the "Red Legion" symbol is orange. Blues look fine.

I can't figure out if this is an nVidia driver issue, a Windows 10 issue, or something glitchy in the Destiny 2 tone mapping. Is anyone else seeing this or have any ideas what's going on? Right now the only way to get true red in the game is SDR mode.

I don't have ME: Andromeda to test to see if the colors are wrong there also, unfortunately.

Edit: Pictures to show the issue added.