I understand where you're coming from, but a white LED only emits so much red light to begin with. What I'm saying is, if you use a good, quality filter to let only red light through, you will notice a huge drop in output. I have a Fenix TK11 with a high quality red filter for it, and the output drops drastically when the filter is added. IMO, you would be better off if you swapped a red emitter into a light or bought a light with a red emitter already installed. Seoul never made any red P7's to my knowledge (could be wrong though), so swapping the white P7 for a red P7 is probably out of the question. Cree makes an MC-E that has 1 red die, but I think you would end up with a flood light using that emitter since the die wouldn't be centered in the reflector. Cree also makes some red XP-E's, XP-C's and XR-C's, but they probably wouldn't work well in that light. What distances does this light need to be effective to? That question might help you in deciding how much throw you need.
