Both the 1906 and 1912 dates were finished in the White (Bright) when new.  Springfield blued the blades in 1917, but only did so for a few years then changed to a parkerized finish.  The Parkerized finish for WWII was a pretty heavy finish and blades and all handle parts looked pretty much the same when done. When redone for WWII, the wood grips would have been changed out for the familiar black (or once in awhile brown) plastic. Your 1912 still shows some of the dark case color at the very end which was common for the bright blades.  The arsenal blue had no delineation between the blade and the hilt. In the photos you've provided, it's difficult to tell if the 1906 was blued or is just in need of a cleaning or both.  My guess in blued for WWI and in need of a cleaning.  The blue used for the bayonet was not a bright, shiny blue, but rather a more subdued, almost black look. The 1912 may still be "in the bright", but also in need of careful cleaning.  What, if any, sort of scabbards did you get with them?

I think Brophy's book on the 1903 Springfield covers the bayonets as well.  I haven't reviewed it in quite a while, but will if you need more complete information.