I have only tracked actual people with NVGs which is a whole different story, but I track game constantly.
I would recommend a Browning Black ice multi-colour LED headlamp used WITH a high lumen output white LED handheld.
The black ice gives good hands free operation, which I like when tracking through thick brush and trying to protect my face and keep my balance.
You get white LEDs x 3(fairly bright)
green- good for map reading and shows up depressions in the ground well(footprints)
red-mostly to preserve night vision and as a good light to use when trying not to spook game(deer don't see well in this spectrum)
blue- this is what I mostly use to track, as blood jumps out at you when viewed under blue light. Shadows fall more noticeably as well allowing you to see trails etc more clearly.
They are not terribly expensive lights, and you can find them all over Edmonton.
But... hunting is different than SAR. Unless the guy is bleeding.....