All the KL1's I've seen have a purplish beam color. I've seen some really bright ones (mine) and dimmer ones. However, they're all consistently blue-ish/purple-ish in color. Don't have much experience with Arc LSL-S to make a comparison, but I'd say the LSL-P's are probably on par in terms of brightness, probably better in color too than the KL1. As far as pocketability, Arc can't be beat.
CM