NATO Black vs Corvus Black

How close are they?

ΔE 7.5, close: similar, with a visible difference side by side. Corvus Black is a little darker, more saturated than NATO Black.

Can I use Corvus Black instead of NATO Black?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Corvus Black is a little darker, more saturated than NATO Black.

Can I use NATO Black instead of Corvus Black?

The same difference applies the other way round: NATO Black is a little lighter, 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.