Said another way, even if the color transition is imperceptible, it might have noticeable effects.
A more complex approach might need to keep higher fidelity color around the edge of objects or some such thing.
So in theory, assuming the display can keep up with eye movements, it should never show you a tightened or limited colour range that you are actually capable of detecting through your eyes.
I suspect it'll be subtly detectable in a couple of ways though, either through rapid eye movements (though I admit I have no clue how fast eye tracking/screen response can be), and secondly (more confidently) that your nose will shine green in the reflected glow of all the green pixels they're cleverly shining where you can't see them directly, and you can definitely see your nose.
I don't use a Quest headset, but on the HP Reverb G2, you can't see your nose at all as long as the face gasket is being properly worn.