ΔE 13.7, fair: the same colour family, but not a straight swap. NATO Black is a little lighter than Corvus Black.
Can I use NATO Black instead of Corvus Black?
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). NATO Black is a little lighter than Corvus Black.
Can I use Corvus Black instead of NATO Black?
The same difference applies the other way round: Corvus Black is a little 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.