The final color of the bluing depends on the steel alloy of the parts being blued, and on the bluing salts that are used. It will be a different color or shade on different parts.
Exactly.
It also depends on the condition of the beads: new or well broken up and the air pressure used. A high pressure blast with newer beads produces a highly stippled surface which will appear very dark after bluing.
If you want a polished slide you have to polish it, or to be more precise, you emery paper it, preferably with the emery paper glued to a flat stick so that your squishy fingers don't push the emery over or into corners and depressions and round those over in a way they were not finished originally.
In short, if you want an original finish, you have to finish in the original way.
Buffing wheels are dangerous weapons in unskilled hands.
Everyone who's ever seen a run of the mill hot tank reblue knows it doesn't duplicate the sort of straw blue you see on original 1911s. Never mind the polishing vs. beading issue.
If you want an original type finish you send the pistol to someone known to do that kind of work and achieve those results, but that kind of work won't come cheap.
We haven't been told anything about the discussion with Epps before the work was done, if there was any discussion. Nor have we seen any photos.
I don't see any sign that glass beading or sand blasting was any part of the original finish on Colt 1911s, which should be fairly obvious to anyone who spends five minutes looking at photos of originals online.
You get what you pay for, and what you ask for.