ΔE 9.2, close: similar, with a visible difference side by side. Gunship Green is a little lighter, more muted, warmer than Dark Green 2 (IJN).
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Gunship Green is a little lighter, more muted, warmer than Dark Green 2 (IJN).
The same difference applies the other way round: Dark Green 2 (IJN) is a little darker, more saturated, 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 Dark Green 2 (IJN) on the colour wheel See Gunship Green on the colour wheel
All matches: Dark Green 2 (IJN) equivalents · Gunship Green equivalents