I don't think that the color of I-16 or MiG-3 is AMT-4. The MiG was built in early 1941 and painted according to standards of 1940.
The piece of I-16 doesn't show a zinc chromate background, so it's unlikely that it's a nitro paint as AMT-4
Hi Xan & Massimo,
I agree with Massimo, both MiG-3 and that I-16 are prewar planes painted according to May 1940 camouflage scheme.
Green paint on metal parts is most likely A-19f. Its colour was 4BO olive green, same as later AMT-4. The only difference is that A19f was glossy while AMT-4 was flat (matte). They were probably pigmented with different pigments, but that is not important for modellers.
Regards,
KL