ΔE 10.2, fair: the same colour family, but not a straight swap. Caliban Green is a little darker, warmer than Guardian Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Caliban Green is a little darker, warmer than Guardian Green.
The same difference applies the other way round: Guardian Green is a little lighter, 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 Guardian Green on the colour wheel See Caliban Green on the colour wheel
All matches: Guardian Green equivalents · Caliban Green equivalents