Black Green vs Unforgiven Green

How close are they?

ΔE 11.3, fair: the same colour family, but not a straight swap. Unforgiven Green is noticeably lighter than Black Green.

Can I use Unforgiven Green instead of Black Green?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Unforgiven Green is noticeably lighter than Black Green.

Can I use Black Green instead of Unforgiven Green?

The same difference applies the other way round: Black Green is noticeably darker.

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.