I don't hunt predators much, but I've watched a little on tv. some things I believe are…
all else being equal, lights dullest to brightest are: red, green, blue and white. filters suck, use led lights. variable beam from spot to flood is nice if it doesn't slip out of adjustment too easily. variable power has some advantages too, as long as you don't have to toggle through half a dozen clicks on the tailcap to get there.
i use red and green but see the pros on tv use white lights successfully. however, that may be for camera purposes?? the trick is not to shine the brightest part of the spot in their eyes. just keep the glow on them. if you're using a gun mounted light to scan, and the cross hairs are line up with the spot, then wait until you're ready to shoot to put the spot on them.
recently I was testing a new ir light. it's very powerful compared to all my other ir lights and it's just in a flashlight body. normally I drive around sneaking up on hogs, but this time I staked out a waterhole and waited on them. two coyotes showed up unaware I was there. when I put the ir light on them they looked right at me. I've also spooked rabbits, birds and numerous hogs with ir lights. if they can see that, they can see everything. sometimes they spook, sometimes they don't.
I think it helps me to be on flat ground where lights from irrigation towers, radio towers, wind turbines, farm houses and distant communities etc are normal. they're used to lights. just don't wave them around like you're trying to flag down a passing motorist. scan slowly so they have less chance to pick up your movement. when you see eyes, leave it on them. if the light doesn't spook them, it will help blind them so they can't see you. when scanning, don't let the light shine on anything they can see, like your vehicle or another person.
if you hunt a stand and spook animals when shining a light on them, try pointing the light up in the air when turning it on and slowly bringing it down. if a game cam is at the feeder, turn your light on when the camera flashes. sometimes tricks work and sometimes they don't... unless of course... you're super D!