Diagnosis
The monitor is likely operating in a non-standard color mode or the graphics card output is mismatched.
How to Fix It
Use the monitor's OSD to reset color settings to the factory-standard sRGB profile. Press the joystick button. Navigate to 'Color Adjust'. Set Color Temperature to 'User'. Then load the sRGB mode directly from the 'Color Adjust' menu. This locks the gamut to a standard for accurate SDR color. Confirm your Windows or graphics driver settings are not overriding this with a custom color profile.
If That Didn't Work
The issue may be a dynamic contrast or gamma setting. In the OSD, navigate to 'Picture Adjust'. Ensure 'Dynamic Contrast' is set to 'Off'. Set Gamma to '2.2'. Set 'Black Stabilization' to the default value of '50'.
Heads Up
For HDR content, enable HDR in Windows Display Settings first, then set the monitor's HDR mode to 'Game' or 'Movie' via the OSD's 'HDR' menu. The monitor's factory sRGB mode is for SDR use only.