ΔE 10.4, fair: the same colour family, but not a straight swap. Ochre is a little lighter, more muted than Olive Drab.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Ochre is a little lighter, more muted than Olive Drab.
The same difference applies the other way round: Olive Drab is a little darker, more saturated.
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 Olive Drab on the colour wheel See Ochre on the colour wheel
All matches: Olive Drab equivalents · Ochre equivalents