'Correct' viewing angle for a computer monitor [or TV] is for your eyeline to be slightly above the centerline of the screen as it reduces neck and eyestrain.
If you're dramatically beyond 'the norm' with your ergonomics there can be a colour shift in the screen, however that has nothing to do with Fences at all and is neither a feature nor a fault of Fences.
There are various online sites with methods or test patterns to set a monitor correctly [or at least determine if it's age/use is such that it's time for a new one].
Check there has been no recent [inadvertent] Video Driver update that has not borked your system.