Could add a toggle I suppose. I don't have any issues with the way it is. It could be a lot worse, they could have made it like Skyrim Night Eye.
an alternative is when light is limited the whole view could go black and white, making it clearer darkvision has kicked in and the trade off between being able to see without lighting your character up vs burning a torch (or a spell) to see normally while reducing your chances to hide
Perhaps only for full darkness, as I understand it in dim light you still see colours. Most areas have some sort of ambient light. Of course if we had full darkness then people playing a race without darkvision would really hate life.
