ΔE 13.0, fair: the same colour family, but not a straight swap. Overlord Olive is noticeably darker, more muted, warmer than Dark DAK Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Overlord Olive is noticeably darker, more muted, warmer than Dark DAK Green.
The same difference applies the other way round: Dark DAK Green is noticeably lighter, 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 Dark DAK Green on the colour wheel See Overlord Olive on the colour wheel
All matches: Dark DAK Green equivalents · Overlord Olive equivalents