There's also two kinds of HA color mismatch issues: 1) color inconsistency across a single piece of metal, i.e. a tailcap is lighter on one side than the other. This should be controlled as well as possible without messing up the yield, but after that, there's nothing more to do about it, except some finished parts can be selected for unusually good consistency. 2) Mismatches between two separate pieces, i.e. a body tube and tailcap are each themselves consistent, but don't have the same color. This can be pretty well controlled by selecting from the pieces that come back in a particular batch to match up colors between mating pieces.
I do think that it's feasible, especially for the premium lights, to select the metal parts for good HA color consistency and match between parts. If it were up to me I would always do that for the premium lights, and if that meant the price had to increase some more, then it would increase. I just don't see much point in paying $30 extra for a light whose only difference from the standard version is the LED came off a different reel.