ΔE 7.4, close: similar, with a visible difference side by side. Russian Green 4BO is more muted than Dark Boot Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Russian Green 4BO is more muted than Dark Boot Brown.
The same difference applies the other way round: Dark Boot Brown 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 Dark Boot Brown on the colour wheel See Russian Green 4BO on the colour wheel
All matches: Dark Boot Brown equivalents · Russian Green 4BO equivalents