Atmospheric Toggles

Would be nice to have a few toggleable switches to adjust atmospheric conditions (like overlays) on maps. Examples would be - Night(Slightly darker overlay), Day (normal/no overlay), Foggy (Light/White contrast to simulate fog) etc. Could even most likely be done to include various weather conditions as well (Rainy, Snowy, etc.)

I do this now by GIMPing my maps, but it's a cumbersome process. Not totally needed in the program, but would be nice and from a programming perspective (all pretty much just transparent type png overlays) most likely not too difficult.

Thanks for listening!
LordV