ΔE 11.7, fair: the same colour family, but not a straight swap. Guardian Green is a little darker, more saturated than IJA Nakajima Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Guardian Green is a little darker, more saturated than IJA Nakajima Green.
The same difference applies the other way round: IJA Nakajima Green is a little lighter, 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 IJA Nakajima Green on the colour wheel See Guardian Green on the colour wheel
All matches: IJA Nakajima Green equivalents · Guardian Green equivalents