ΔE 8.0, close: similar, with a visible difference side by side. IJN Black Green is more saturated than War Master Green.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). IJN Black Green is more saturated than War Master Green.
The same difference applies the other way round: War Master Green is 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 War Master Green on the colour wheel See IJN Black Green on the colour wheel
All matches: War Master Green equivalents · IJN Black Green equivalents