However, I couldn't get my GTX 1070 to work with HDR and was stuck at 4:2:0 on the TCL but seemed to work on the Samsung. I have two HDR tvs, Samsung MU6500 and TCL 42S425, both are rated for and HDR. I checked every Nvidia driver from 419.17-431.70, all reacted the same with my setup. My tv has two hdmi edid modes: mode one couldn't get rgb but mode two could. I had my 50'' 4k tv working with rgb for over a year and now all of a sudden im stuck with the same settings as you. If I set the refresh rate to 30Hz, I am able to select more color options.Īny idea why at 4k x 2k, 3840 x 2160 and 60Hz I am unable to access more color settings? Could it potentially be the HDMI cable? I think the one I'm using is relatively old, though I'm not sure. From what I've read, YCbCr420 is also limiting the color output and does not look as good as some of the other available settings. This prohibits being able to turn on Windows HDR. At 4k resolution (3840 x 2160) and 60Hz refresh rate, I am unable to change any color settings in the Nvidia Control Panel.