ΔE 7.7, close: similar, with a visible difference side by side. Dark Green Kawanishi is a little lighter, more saturated, cooler than Dark Feldgrau.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Dark Green Kawanishi is a little lighter, more saturated, cooler than Dark Feldgrau.
The same difference applies the other way round: Dark Feldgrau is a little darker, more muted, 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 Kawanishi on the colour wheel
All matches: Dark Feldgrau equivalents · Dark Green Kawanishi equivalents