- For this to work, you have to be able to keep it above 48 FPS.
- Nvidia you have to use Display Port for Free Sync support
Have you installed the monitor's drivers?
I could see some type of compression maybe being necessary and causing color issues, but this is only a 1080p monitor so that doesn't seem likely. Have you gone through the monitor's menu and looked at anything that might alter the image?
Only a 6-bit panel, that might not help with the colors too much.