I certainly know that the British SAS use blue light for any close quarters illumination, both for the alertness it brings and because the short wave-length light doesn't travel distance perceivably well to the naked eye, ensuring the enemy is 'kept in the dark'.
Frankly I'll stick with caffeine. I have to say that I would have loved to participate in this challenge but caffeine is definitely my 'crack'. Even the simple though of going without it for an hour is too much.
