tamiya acrylic nato colors equivalent model master acrylic

Aircraft Interior Black works for the NATO Black

Russian Armor Green, or Grun RLM 62, appear to be somewhat close to NATO Green, but are not exact matches

Rotbraun RAL 8012, a newly issued color in the MMA line, would be a great match for NATO Brown if you can get it, if not, Leather darkened up a bit will work.

The NATO colors weather quite a bit over time, although not as badly as the older MERDC colors.

You might even be able to get away with Medium Green 34102 for a faded version of NATO Green. It's a crying shame that MM discontinued the Polly Scale line- they had great versions of the NATO colors in acrylics.