A cute idea for if they ever add a big daddy from bioshock. If a survivor is outside the terror radius; the red stain is green, if the survivor is inside the terror radius; the red stain is orange, and if the survivor is in chase them the red stain is red.

This is because in bioshock the big daddy emits a light with different colours based on it's mood similar to the red stain. Green for calm/happy, orange for cautious and red for angry.

Not a major important gameplay idea and alot of people may not even notice it but I thought it would be a nice reference to the game.