ΔE 7.1, close: similar, with a visible difference side by side. Medium Olive is a little lighter, warmer than NATO Green.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Medium Olive is a little lighter, warmer than NATO Green.
The same difference applies the other way round: NATO Green is a little darker, cooler.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See NATO Green on the colour wheel See Medium Olive on the colour wheel
All matches: NATO Green equivalents · Medium Olive equivalents