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