I think especially for VR porn it makes sense to get an accurate color representation with as natural colors as possible and an appropriate brightness to improve the immersion.
DeoVR offers a setting for this, among other things that you can select the "Color Space". Since probably all VRPorns are currently delivered in SDR (not HDR... we are not there yet...), the only sensible setting here is Rec 709. SDR videos are delivered in this color space and it actually makes little sense to choose a different color space. The ST.2020 color space, for example, is intended for HDR videos and is significantly larger, but it is not a good idea to display a Rec 709 video in the St.2020 color space, since here only all colors are scaled and thus almost everything is over-saturated.
It would also be obvious to simply select the color space of the respective headset. So if I use a Quest 2, you could just select "Quest". However, this approach is just as pointless, since the native color space of the Quest 2 is slightly larger than Rec 709, which is what the videos are actually mastered with. So again a scaling takes place and you get falsified colors displayed.
Another useful tip is to set the brightness of the headset as low as possible (for the Quest 2: 0). The idea behind this is simply that you are in a completely darkened room in the VR headset anyway and any increase above the 100-nits reference brightness is pointless for SDR content and does not contribute to the image quality. Why this is so: In SDR you have very limited brightness reproduction anyway, and our TVs only overdrive it to compete against daylight or strong ambient light - neither of which is present in the headset, and too much brightness would only hurt picture quality. You don't lose any details with a low brightness. After all, we are not in an HDR context.
