ΔE 12.1, fair: the same colour family, but not a straight swap. IJA Grey Green is a little lighter, more muted, warmer than Light Imperial Khaki.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). IJA Grey Green is a little lighter, more muted, warmer than Light Imperial Khaki.
The same difference applies the other way round: Light Imperial Khaki is a little darker, more saturated, 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 Light Imperial Khaki on the colour wheel See IJA Grey Green on the colour wheel
All matches: Light Imperial Khaki equivalents · IJA Grey Green equivalents