ΔE 7.8, close: similar, with a visible difference side by side. Park Green Flat is a little darker, more saturated, cooler than IJA Nakajima Green.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Park Green Flat is a little darker, more saturated, cooler than IJA Nakajima Green.
The same difference applies the other way round: IJA Nakajima Green is a little lighter, more muted, warmer.
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 IJA Nakajima Green on the colour wheel See Park Green Flat on the colour wheel
All matches: IJA Nakajima Green equivalents · Park Green Flat equivalents