Ok so I have been doing some investigative work the last few days and have discovered a change that the recent Windows Update has had in the way colours are displayed when you siwtch to 10-bit colour output in Nvidia Control Panel vs the default 8-bit which on an Nvidia card uses FRC and is "technically" near 1:1 as native 10-bit, which has visually been the case for all these years from the AW3423DW to this QF.
It;s subtle enough to slip by but I did notice it as when things are even slightly off, I tend to notice those things and they bother me until I find the cause lol.
The change in whatever MS did seems to have affected the colours in that when using 10-bit now colours look washed out, most noticed in the green:
8-bit:
10-bit:
These are just phone pictures of the screen but it's good enough to demonstrated. I was originally going mad as could have sworn the colours were feeling washed out to my eyes. Checked ICC profiles, only the HDR calibrated one there which is only used in HDR mode, checked NV App and NVCPL settings, all good, checked DP cable, all good, reinstalled NV drivers, no change, checked OSD settings on the QF and all good.... It was this evening when I out on a whim decided to flick the bit depth to 8-bit (Default for Windows anyway) that it was back to the correct colours that I was seeing before when on 10-bit.
So either the QF has coincidentally started to ignore a 10-bit signal for some reason and make colours look washed out slightly at the exact same time a new major Windows Update came out, or MS are up to no good.
Can anyone else running the latest Win11 test this?
All you have to do is flick this to 8-bit if you are on 10 and apply and look at an image that has a lot of primary colours on (my test chart is below). If you already are on 8-bit then flick to 10 and compare.
Chart image (PNG so lossless):
For reference, I am in Creator mode in the OSD and using sRGB.
For clarity, this does not pose an issue as such, since 8-bit is more than fine on an Nvidia card so I will just continue using that until MS fix whatever it is they did assuming it's a MS issue and not coincidental.