I personally love LED's for leak checking when required, but since I live in the bush and have to pack everything willy nilly hither and yon on a moments notice I tend to stick with ye ole Maglite. Reason being since I fill out of barrels for the most part it is far more accurate in determining proper color of the fuel and the focus of the beam is very handy in determining the quality of the barrel lining...very important issues w/ barrels especially in the cold.
At 15$ a piece it doesn't hurt so much when you lose one, and trust me, if you live in a tent on occasion...you will.
As for the Color thing I wouldn't have a clue. I fly Day VFR in Northern Canada....Why the HELL would I want to do it at night? LOL
BWB