Benjy, Kentucky TJ,
I have a related post asking about bulb options in the LED's. Maybe LB-hntr will chime in here, he's the light authority. He PM'd me and said for blood trailing at night you need what the manufacturers refer to as the "neutral" or "natural" white option, not the "cool" white. My SureFire makes blood glow. It's several years old and was a gift from my son, so I guess I got lucky on the color. The technology has left my model behind, now you can get 700-800 lumens max output. I'm getting an Eagle Tac D25LC2 and he said to get the XM-L2 bulb, not the XP. Hope this helps.