Going to chime in on this one. I heard the term BUFF was first used in WW2 on the shiny aluminum skin that had to be washed and waxed, then BUFFed to make it extra shiny. That way the sun would make the plane stand out in the blue sky like a shooting star.
The brass in HQ were determined to make sure the Luftwaffe wouldn't get lost. That way they had a bright shiny beacon to visually home in on. Unfortunately, the LW failed to order surplus sunglasses. The brightness of the shiny skin blinded them making them easy targets in the last few months of the war.
To this date, I have found no official data to validate that theory.
