So I had gone pretty far south of Boston the other day looking for a place to make a homestead when I got the tutorial popup about being far from civilization and the gradual drain on my humours started. Being a newbie with low stats I left, later on I apparently entered the darkness again however there was no indication that I had entered until I noticed my stats slowly dropping.
I've read that the screen gradually gets darker the further you move into the darkness, but I didn't see any noticeable difference in lighting from the area classified as darkness vs non-dark. (Although I didn't go very far in before turning back each time)
Perhaps some sort of on screen indication that one has entered the darkness would be helpful? Like a persistent icon that stays on screen while your in an area classified as darkness.