PSA: For 39GX950B - try out Personalized Mode to improve color accuracy in HDR/SDR.
I have LG's 39GX950B for almost a week now, and it was a non-stop struggle for me trying to get its color saturation "right".
I tried many various combination of monitor/driver/calibration settings, icc profiles, ColorControl, Nvidia Control Panel, what not and I simply could not land anything satisfactory as far as colors went. I even tried that all with LG's AI Scene Optimization on, out of sheer desperation.
That is until I watched Monitors Unboxed review of this monitor and the reviewer dropped a golden tip there: try out Personalized Picture mode!
And I have to say - that mode actually gave me the closest to great result so far, to the point I just will keep running that and not look back.
It has a trade off of turning off LG's DAS mode, which supposed to give you ultra-low latency, but it just does not seem to matter any, or at least anything perceptible for me - well worth finally having good color saturation.
Now, of course such things are personal taste, but IMO - Personalized Picture mode + (optionally) Black Stabilizer at 45 instead of 50 is the play.