As Jim said there are a lot of companies today that use case "color". The first that comes to mind is Ruger on their Vaqueros. The case color on these guns has received a well deserved reputation, in my opinion, for very rapid wear. All of the Italian companies making Colt clones, to my knowledge, actually case harden their guns.
If you do a search in The Smithy forum on case hardening you will find some very interesting and educational past discussions. It is a topic that is much discussed that I never grow tired of. There is nothing, in my opinion, so beautiful as good case hardening matched with a good blue job.
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Gunslinger
I was promised a Shortycicle and I want a Shortycicle!