wtf is "tag"?

With the popularity of Black over the last couple decades (individual treatment not too important). Why are we still so limited to Blue and SS for small parts? Just Frustrated trying to find a simple cheap part. (recoil spring plug)

I find it interesting that the two handguns that are always in a holster with me; at the range, ranch, in the office, out to dinner, etc. are designs that date to 80 years old or older. Granted there have been a couple, "major" design changes; an external extractor and FP safety with the P-35...