ΔE 8.4, close: similar, with a visible difference side by side. Shadow Blue is a little lighter, cooler than Necromancer Cloak.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Shadow Blue is a little lighter, cooler than Necromancer Cloak.
The same difference applies the other way round: Necromancer Cloak is a little darker, warmer.
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 Necromancer Cloak on the colour wheel See Shadow Blue on the colour wheel
All matches: Necromancer Cloak equivalents · Shadow Blue equivalents