Great Photos!
OK, conjecture: Top three rifles, charcoal blue, next three rust blue with rust bluing over case colored takedown forend (hard steel-hard to rust blue, doesn't wear well, try a needle file in a hidden place.) All brls probably rust blued.
The blue on my old Colt looks very much like the blue-turning-brown of your second photo.

Does the third vintage photo show a skeletonized 99?

I'm going to rethink my knife and cartridge belt choices for mule deer hunting this year!
Best,
Steve