ΔE 11.5, fair: the same colour family, but not a straight swap. Dark Green is a little darker, more muted than Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Dark Green is a little darker, more muted than Green.
The same difference applies the other way round: Green is a little lighter, 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 Green on the colour wheel See Dark Green on the colour wheel
All matches: Green equivalents · Dark Green equivalents