You know, I don't honestly know, but someone here will know for sure. I think it depends on what level of "finished" you get on the part you are ordering.
I would imagine that even if you got a blued model, once you did what you needed to do to get all the parts in place and working properly, the perfectionist would probably want it stripped down and re-blued anyways.
Brett used to build 1911's all the time, but he stopped before I started hanging out there, so I have never seen one from the start through the finished project, just changes to ones here or there along the way.
Supposedly a guy from a neighboring city called like 2 weeks ago and offered big money to have a 1911 made by Brett to his exact specs, ( it's an IPSC Race Gun ) so I might be able to see some of the process and maybe post some pictures.
I can't honestly say what you would and would not HAVE to do on a kit build though - I am not experienced in it hands on.