Some commercial makers of the .45 Government (.45 Schofield) used the .46 Colt head bunter, so they are marked ".45 Colt".
I believe that you are talking about the short Colt cartridges currently under discussion, not the .45 Schofield/S&W rounds. The short Colt cartridges were similar in case length to the Schofield rounds but with noticeably different rim dimensions and were marked .45 Colt.
The Schofield rounds were marked .45 S&W or .45 Govt, but not .45 Colt.
If you look at the pictures in the opening post of the linked thread you can see what I'm talking about.
The two cartridges on the left are the .45 Schofield/.45 S&W/.45 Govt cartridges and even in the pictures is easy to see that the rim dimensions are significantly different from the 3 cartridges on the right which are the .45 Colt in short and long varieties.