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