ΔE 6.4, close: similar, with a visible difference side by side. Night Blue is a little lighter, more saturated than Black.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Night Blue is a little lighter, more saturated than Black.
The same difference applies the other way round: 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 Black on the colour wheel See Night Blue on the colour wheel
All matches: Black equivalents · Night Blue equivalents