That's interesting, I would have thought that the warmer color would be at the most important in a throw-light, since you need to maximize the benefit of every single photon that reaches your eyes. Does a lens typically distort the color that much? I've never experimented with lenses + warm-whites... I'll have to try it a little tonight.
I like warm-white emitters not for white-walling, (I actually prefer cool-whites for that) but for actually distinguishing between objects in a chaotic outdoor setting. I never thought about it, but I'm surprised that some of the CPF members that specialize in throwy lights haven't modded a few heavily-driven XR-Es with Q3-5As. At least for those whose eyes react to light similarly to mine, it would make them more useful in real life.
There is chromatic aberration, or a blue "fringe" surrounding the edge of the beam, but other than that, the lens doesn't really "distort" the color at all.
The difference is that for most white LEDs, light that is emitted directly "out the front" tends to pass through a narrower layer of phosphor, thus is slightly cooler. Light that is emitted toward the edges will pass through a thicker layer of phosphor, and willl thus be warmer. For a device utilizing a warm white LED, which tends to have a thicker layer of phosphor anyway, this difference in tint between the direct beam, and the lateral beam will be more pronounced. So yes, light that is captured using aspheric will tend to be "cooler". That's not really "distortion" do to the lens, just the nature of the LED devices.
Actually right now, one of my most used lights is a 5a MC-E in a Aspheric mag. I actually greatly prefer the neutral over the cool in the throwing lights for the reason that you mention -- it is using a light outdoors, whiere most objects tend to reflect little in the blue, and more in the green and red, where the benefit of having the neutral tint is more greatly apprecited. This has nothign to do with "white wall hunting", in fact, quite the contrary. The cool white aspherics tend to look nicer on a white wall, the neutral white aspherics tend to look the best for actual use.
