ΔE 8.6, close: similar, with a visible difference side by side. Dark Green is a little lighter, cooler than Dark Feldgrau.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Dark Green is a little lighter, cooler than Dark Feldgrau.
The same difference applies the other way round: Dark Feldgrau 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 Dark Feldgrau on the colour wheel See Dark Green on the colour wheel
All matches: Dark Feldgrau equivalents · Dark Green equivalents