I used to have a link to sovietwarplanes.com, but it's a redirect to ads now and doesn't work. It was full of photos and correct color samples for the early Soviet AC. Now the best I can do is IPMS. When I built both of my early Soviet birds the site showed the cockpits in a light grey color and had unrestored photo examples. I found that the RLM02 was a close match. I wish that site still worked, it was the best thing I've seen for the VSS stuff. I guess I'll have to start looking hard again.
I FOUND IT !!!!
http://massimotessitori.altervista.org/sovietwarplanes/pages/mig3/mig3.html
This is a treasure trove of information on the Mig 3 and you can dig around and really learn a ton from this site. I also found the photo of the correct interior colors. The sides and floor were the color like RLM02, the front of the pit, inst panel and tubing, was black, seat was dark green. If you look at the photo you'll see the grey green on the far left tubing and some of the boxes. As you can see there were 3 primary colors in the early planes. Most people paint them light grey and that's it, but they are grey/green, dark green and black. There is not alot of detail in most of these kits so the colors help make the lack of detail more interesting.
This is a restored bird, but the color scheme is close to correct from what I've found in my research.
I really need to build another one. I wonder how the lend lease AC were painted inside? Hmm.?
BK
And since yours in Red O2, you might find this link helpful.
http://massimotessitori.altervista.org/sovietwarplanes/pages/mig3/red02.html
Oh, and I think you kit looks stellar!! You have really lit a fire under me to build another Mig.