In the SW part, do you see the same appearance assignments on each surface body? Ie can you expand the surface bodies folder in your last screenshot?
No appearances were assigned to the surface bodies.
So I copied the non-bronze appearances (blue shirt, etc.) to those bodies.
But the Visualize import stayed one color.
I have attached the part/assembly pack and go in case you want to experiment.
Working Man Assy.zip 18.8 MB
I have had a similar issue with assembly files, I use Export Advanced for Everything because I am constantly updating products in my "Scene"
My fix was to go into the assembly and give a wild appearance Color to each Body I wanted a separate color.
Note Bill and I are using libraries located on different Hard drives than the program is installed to.
This might have something to do with how Visualize imports the project.
Depending on the number of changes I make to the assembly file, I often lose complete parts of the assembly. (which disappear from the project Tree)