ΔE 6.6, close: similar, with a visible difference side by side. Khaki Green is a little darker, more saturated, cooler than Mid Feldgrau.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Khaki Green is a little darker, more saturated, cooler than Mid Feldgrau.
The same difference applies the other way round: Mid Feldgrau is a little lighter, 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 Mid Feldgrau on the colour wheel See Khaki Green on the colour wheel
All matches: Mid Feldgrau equivalents · Khaki Green equivalents