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