I have a 4K TV, and HDR enabled on Windows 10 appears washed-out. Playing around with different color space options didn't help. If I use MPC-BE with madVR and full-screen a HDR video with HDR enabled though, it looks pretty good, and if I either window it or just have the OSD display for a bit, it reverts back to the washed-out state. So I'm thinking in order to fix this, I need to report all content to the display as video. With NVIDIA, I recall this being easy from their control panel (info). Is this possible at all on AMD?