Evil Flesh vs Nocturna Shadow

How close are they?

ΔE 7.4, close: similar, with a visible difference side by side. Nocturna Shadow is a little lighter, more muted than Evil Flesh.

Can I use Nocturna Shadow instead of Evil Flesh?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Nocturna Shadow is a little lighter, more muted than Evil Flesh.

Can I use Evil Flesh instead of Nocturna Shadow?

The same difference applies the other way round: Evil Flesh is a little darker, more saturated.

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.