Hi Sipder,
Thank you for posting in Microsoft community.
I understand that you're having issues with your secondary monitor where the color changes from red to orange whenever you switch to HDR mode.
According to an existing forum that I found, this is a common behavior of this specific monitor, to the point where most users are just switching from HDR to SDR.
Here's the existing forum for your reference:
https://www.reddit.com/r/Monitors/comments/1h7j...
Please see if you have an available firmware update on your monitor and update to the latest version.
If you already have the latest version, I would recommend that you contact Philips support to further investigate on your issue.
http://www.support.philips.com/support/contact/...
Regards,
Alvaro