ΔE 6.8, close: similar, with a visible difference side by side. IJN Deep Dark Green is a little darker than Green FS34092.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). IJN Deep Dark Green is a little darker than Green FS34092.
The same difference applies the other way round: Green FS34092 is a little lighter.
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 Green FS34092 on the colour wheel See IJN Deep Dark Green on the colour wheel
All matches: Green FS34092 equivalents · IJN Deep Dark Green equivalents