doubleriflejack: in modern firearms, CCH is done a lot of times to simply produce the colors that used to be a by product of carburizing low carbon steels. Not "needed" for strength, but its beautiful and nostalgic(to my eyes at least). But I do believe that there are lacquer type coatings that can be used to protect/preserve the coloring from wearing out too fast, Galazan products sells a case color lacquer.

More than likely, I will be contacting Turnbull and asking them for clarification(my plan was to have them do my CCH either way, they are the top of the line quality). Whilst reading through posts earlier, I did see a post by mr Bradshaw and he said he uses 8620 steel for parts that he intends to CCH, which may be the way to go.