You're right, Halogen are better than most LEDs due to their Color Rendering Index (CRI) value is 100 for accurate colors. Many LEDs are around 60 - 80 which will wash out the colors. High CRI LEDs exist, but many aren't for long range to suit most hunting applications. If you knew how to modify a flashlight then you could source a circuit board / driver and a suitable LED.
The only higher CRI LEDs I'm aware of, for longer range, are the following:
Cree XHP35.2 HI 90 CRI variant
Cree XHP50.2 HI "
Luminus SST20 4000K and below are high CRI
There'll be others, jus