ΔE 10.3, fair: the same colour family, but not a straight swap. IJA Grey Green is a little lighter, warmer than Contagion Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). IJA Grey Green is a little lighter, warmer than Contagion Green.
The same difference applies the other way round: Contagion Green is a little darker, 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 Contagion Green on the colour wheel See IJA Grey Green on the colour wheel
All matches: Contagion Green equivalents · IJA Grey Green equivalents