ΔE 6.3, close: similar, with a visible difference side by side. IJN Black Green is a little darker, warmer than Highland Moss.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). IJN Black Green is a little darker, warmer than Highland Moss.
The same difference applies the other way round: Highland Moss is a little lighter, 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 Highland Moss on the colour wheel See IJN Black Green on the colour wheel
All matches: Highland Moss equivalents · IJN Black Green equivalents