ΔE 12.9, fair: the same colour family, but not a straight swap. NATO Green is more muted, warmer than Dark Emerald.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). NATO Green is more muted, warmer than Dark Emerald.
The same difference applies the other way round: Dark Emerald is more saturated, 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 Dark Emerald on the colour wheel See NATO Green on the colour wheel
All matches: Dark Emerald equivalents · NATO Green equivalents