ΔE 7.0, close: similar, with a visible difference side by side. USAF Green is more muted than RLM 83 Dark Green.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). USAF Green is more muted than RLM 83 Dark Green.
The same difference applies the other way round: RLM 83 Dark Green is more saturated.
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 RLM 83 Dark Green on the colour wheel See USAF Green on the colour wheel
All matches: RLM 83 Dark Green equivalents · USAF Green equivalents