mig Paint

Is there a FS number assigned to it?

These colors are pretty much self-explanatory since these colors are readily available

A.MIG-032 = Black

A.MIG-033 = Tamiya XF-85 Rubber Black

A.MIG0-35 = Humbrol 173 Track Color

A.MIG-045 = Gunmetal

A.MIG-046 = Flat Black

A.MIG-047 = White

A.MIG-049 = Red

A.MIG-043 = Rust

A.MIG-070 = Medium Brown

A.MIG-191 = Steel 

A.MIG-194 = Aluminum

A.MIG-197 = Brass

A.MIG-199 = Copper

Vallejo has a WW2 Russian paint set for WW2 Russian tanks:

http://www.acrylicosvallejo.com/en_US/afv-russian-green-4bo/family/17/118

Hello!

While I understand you are trying your best to be accurate, I don't think you need to be so strict when it comes to colour conversions. When you do some research on the net as to how the original would look like, you'll find a lot better information and then you need to form your own opinion on how to best reproduce russian green 4BO (with weathering it shifts its colour anyway), or what exact metallic shado to use on tracks. An exact paint shade in the instructions just negatively affects your creativity!

Good luck with your build, hope it helps and have a nice day

Paweł