There is some debate on the red for night vision thing. Everybody jumped on red light because it can be used while processing camera film, but there is evidence supporting blueish-green (505nm to 510nm) as a superior night-vision color because you can see as well with a only a tiny amount of bluegreen light than you can with a whole bunch more red light.

Some also say that it's not necessarily the color that preserves night vision but the overall brightness. So, if you use an extremely dim white light, supposedly your night vision won't be any more compromised than it would be with a brighter red or bluegreen one.

Now, for flashlights. My take is headlamps tend to be too big and heavy so instead I have a 1xAAA LED flashlight. It has three modes: 4 lumens low, 20 lumens medium, and 70 lumens high. The low is actually too bright to preserve night vision for close work, but works ok for shining on the ground and walking around when (mostly) dark adapted. It has a clip that can be used 'reversed' and clipped to the bill of a baseball cap and thus become a headlamp without a lot of weight and bulk (assuming you're wearing a cap anyway). It'll also shine continuously for over 24 hours on low using a featherweight lithium AAA battery, which to me is amazing.

As someone already mentioned, candlepowerforums.com has a mind-boggling amount of info on tiny and bright LED flashlights. There are literally dozens if not hundreds of lights out there to choose from.