ΔE 6.8, close: similar, with a visible difference side by side. IJN Deep Dark Green is more muted than Dark Emerald.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). IJN Deep Dark Green is more muted than Dark Emerald.
The same difference applies the other way round: Dark Emerald 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 Emerald on the colour wheel See IJN Deep Dark Green on the colour wheel
All matches: Dark Emerald equivalents · IJN Deep Dark Green equivalents