AMT-4 (A-24m) Green vs Army Green

How close are they?

ΔE 7.6, close: similar, with a visible difference side by side. Army Green is a little lighter, cooler than AMT-4 (A-24m) Green.

Can I use Army Green instead of AMT-4 (A-24m) Green?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Army Green is a little lighter, cooler than AMT-4 (A-24m) Green.

Can I use AMT-4 (A-24m) Green instead of Army Green?

The same difference applies the other way round: AMT-4 (A-24m) Green is a little darker, warmer.

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.