ΔE 7.4, close: similar, with a visible difference side by side. Flat Green is a little lighter, cooler than AII Green.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Flat Green is a little lighter, cooler than AII Green.
The same difference applies the other way round: AII 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.
See AII Green on the colour wheel See Flat Green on the colour wheel
All matches: AII Green equivalents · Flat Green equivalents