ΔE 7.8, close: similar, with a visible difference side by side. Fern Green is a little darker, more saturated than Dark Olive Green FS-34130.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Fern Green is a little darker, more saturated than Dark Olive Green FS-34130.
The same difference applies the other way round: Dark Olive Green FS-34130 is a little lighter, more muted.
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 Olive Green FS-34130 on the colour wheel See Fern Green on the colour wheel
All matches: Dark Olive Green FS-34130 equivalents · Fern Green equivalents