I have doubts as to the viability of your scheme as Windows is pretty
aware of, and sensitive to, its environment.

WRT your dead pixel question, I would think that you could get to the
same point with The Gimp. You could create 3 JPEG images each filled
with one primary color (0,0,255), (0,255,0), and (0,0,255) and then
view them full screen.