ΔE 13.5, fair: the same colour family, but not a straight swap. Ink Black Green is noticeably lighter, cooler than Olive Ink.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Ink Black Green is noticeably lighter, cooler than Olive Ink.
The same difference applies the other way round: Olive Ink is noticeably darker, 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 Olive Ink on the colour wheel See Ink Black Green on the colour wheel
All matches: Olive Ink equivalents · Ink Black Green equivalents