I would imagine (to to it properly) you will need separate map textures created for TOD
perhaps 5 classes sunrise midday evening dusk and night to make it "realistic" but that's a big ask.
Or
The mission map loading TOD reference triggers a colour to black and white gammut so the game drops the global colour reference internally.
auto switching the video setting in IL2 and not using the ATI Nvidia software to control it.
Quite a bit of work, but you could just turn the monitor colour down locally to suit your eye,
as you can imagine there will be as usual people complaining about its too grey or not grey enough etc etc
