ΔE 11.6, fair: the same colour family, but not a straight swap. IJN Green Nakajima is a little darker, more muted than Castellan Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). IJN Green Nakajima is a little darker, more muted than Castellan Green.
The same difference applies the other way round: Castellan 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 Castellan Green on the colour wheel See IJN Green Nakajima on the colour wheel
All matches: Castellan Green equivalents · IJN Green Nakajima equivalents