ΔE 6.3, close: similar, with a visible difference side by side. Midnight Olive is a little lighter than Cold Black.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Midnight Olive is a little lighter than Cold Black.
The same difference applies the other way round: Cold 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.
See Cold Black on the colour wheel See Midnight Olive on the colour wheel
All matches: Cold Black equivalents · Midnight Olive equivalents