I spent a few hours playing with the image space modifier system but that colors the entire view.
I looked at overlays and that is above my skill set.
Any Other way to get a flash of red on the edge of the screen (this is for pain simulation)? If there is no other way I will do what I did in *Oblivion but that was very crude and I hoped Skyrim would have a better and straightforward method.
* spawn and deleted a 2d sprite type object in front of the camera.