ΔE 8.4, close: similar, with a visible difference side by side. Mid Feldgrau is a little darker, more muted, cooler than Olive Green.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Mid Feldgrau is a little darker, more muted, cooler than Olive Green.
The same difference applies the other way round: Olive Green is a little lighter, more saturated, 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 Olive Green on the colour wheel See Mid Feldgrau on the colour wheel
All matches: Olive Green equivalents · Mid Feldgrau equivalents