I've replied to your message also please check the post on Intel Forum, it has details including DxDiag.
Dell XPS 9570
Intel UHD 630
Nvidia GeForce 1050 Ti
4K UHD Touch
16 GB RAM
AndrewG from Intel is advising:
"When using HDMI® the only way to get this option would be to either get the OEM (DELL™) to modify the driver so it auto-disable YCbCr on supported displays instead of auto-enable (our generic driver is configured to auto-enable) or modifying the Windows® Registry to change the right key to modify the behavior."
I know how to use regedit.exe to change registry, just don't know what values to change.