ΔE 6.3, close: similar, with a visible difference side by side. Dark Green RLM71 is a little lighter, warmer than Nº9 Olive Drab (FS33070).
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Dark Green RLM71 is a little lighter, warmer than Nº9 Olive Drab (FS33070).
The same difference applies the other way round: Nº9 Olive Drab (FS33070) is a little darker, 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 Nº9 Olive Drab (FS33070) on the colour wheel See Dark Green RLM71 on the colour wheel
All matches: Nº9 Olive Drab (FS33070) equivalents · Dark Green RLM71 equivalents