I did receive this reply from the dev which fixed the issue on my Switch 2, hope this helps you too!
- Go to System Settings on your Switch home screen.
- Scroll down to TV Settings.
- Find RGB Range. It is usually set to "Automatic" by default.
- Change it manually to "Limited Range" (or test "Full Range" if Limited doesn't work).
In 90% of cases, forcing this setting will make the picture instantly snap back to those deep, crispy colors without that milky/bright filter.