Windows 10: External display turned black after turning on HDR and I can't turn it off

I connected my work laptop to an external display at home via a usb c dock. I was using the built in display and external display in extended mode. I looked through the display settings in windows 10 and thought I'd try HDR on the external display since it is HDR capable. I toggled HDR on and the external display turned black. After a short time the external says it's not receiving signal and turns off. When I look at display settings for the external display in windows, there is no option to turn off HDR. If I switch to mirrored display mode both displays work. If I disconnect power from the

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Black display after inadvertently turning on HDR

I got a black display after inadvertently turning on HDR. I was adding an external 4K monitor to my laptop. I clicked on HDR inadvertently. Both screens started flashing then went black. I rebooted. Lenovo boot logo comes up but the laptop screen stays black. I get a cursor on the external monitor but I don’t on laptop screen. Tried rebooting while repeatedly pressing F8 to boot in safe mode but screen stays black. So I’m locked. What can I do?

 

Extended Display blacks out after turning on the windows HDR option

I have connected an extended display which supports both 4K and HDR and whenever I'm turning on the "Use HDR" for the display under the Windows HD color settings, the extended display blacks out. It comes back after I turn off the HDR. Need help to fix this issue?

 

Turning HDR on/off programmatically

I need way to turn HDR on/off programmatically instead of using Windows Display Settings (https://support.microsoft.com/en-gb/help/4040263/windows-10-hdr-advanced-color-settings).

Is there a COM object or API that I can call or use to turn HDR on/off in my application code?

Thanks.