Necromancer Purple vs Blue Violet

How close are they?

ΔE 8.5, close: similar, with a visible difference side by side. Blue Violet is more saturated than Necromancer Purple.

Can I use Blue Violet instead of Necromancer Purple?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Blue Violet is more saturated than Necromancer Purple.

Can I use Necromancer Purple instead of Blue Violet?

The same difference applies the other way round: Necromancer Purple is 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.