[CONFIG] Darkness Vision Effect off

[KiraImmortal]

my question is simple. how can i turn on the blue darkness vision effect (when i'm standing in darkness and no lantern is used), to make the screen pitch black when i'm standing far from any light? like in AMFP, but i want to keep the sanity drain effect, i only want to turn down the blue vision. i suppose something must be changed in the game.cfg. i'm making a full conversion mod and i'd like to warn the player with this to save the oil and tinderboxes, because there will be total darkness in the maps.