As title says, suggestion is making nights darker than they are, optimaly adding some kind of wearable, TOGGABLE ofc, lanterns (attached to belt) or torches(but that would cost u one weapon slot)...
there could also be some adjustments to that like lowered eye sight of guards etc.
this screenshot is from coldharbour, tower Q when rescuing King... i consider it as optimal daaaarkness for cave with no lights, open area would be a little bit lighter, all depending on moon, weather and surroundings
(sweetFX being used)