ΔE 14.2, fair: the same colour family, but not a straight swap. Ink Black Green is a little lighter, more saturated than Opulentus Black.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Ink Black Green is a little lighter, more saturated than Opulentus Black.
The same difference applies the other way round: Opulentus Black is a little darker, more muted.
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 Opulentus Black on the colour wheel See Ink Black Green on the colour wheel
All matches: Opulentus Black equivalents · Ink Black Green equivalents