It's possible to glitch the visual filter that appears when your player character dies so that it persists in normal gameplay. If you are on foot, you will always load into the game facing north, so to perform this glitch, you need to be facing a wall to the north. While facing it, take out an RPG, save your game, then load back into the game while attempting to fire it. You should die from the explosion as the game loads back in, and you will respawn with the death visual filter, which will remain on-screen until you die again.