ΔE 12.0, fair: the same colour family, but not a straight swap. IJN Deep Dark Green is more muted, warmer than Ocean Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). IJN Deep Dark Green is more muted, warmer than Ocean Blue.
The same difference applies the other way round: Ocean Blue 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 Ocean Blue on the colour wheel See IJN Deep Dark Green on the colour wheel
All matches: Ocean Blue equivalents · IJN Deep Dark Green equivalents