ΔE 8.7, close: similar, with a visible difference side by side. Fern Green is a little darker, warmer than Russian Green 2.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Fern Green is a little darker, warmer than Russian Green 2.
The same difference applies the other way round: Russian Green 2 is a little lighter, 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 Russian Green 2 on the colour wheel See Fern Green on the colour wheel
All matches: Russian Green 2 equivalents · Fern Green equivalents