ΔE 7.6, close: similar, with a visible difference side by side. Dioxazine Purple is a little lighter, more saturated than Naggaroth Night. They are different kinds of paint: Citadel Naggaroth Night is an opaque base/layer paint and Golden Dioxazine Purple is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Dioxazine Purple is a little lighter, more saturated than Naggaroth Night. They are different kinds of paint.
The same difference applies the other way round: Naggaroth Night 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 Naggaroth Night on the colour wheel See Dioxazine Purple on the colour wheel
All matches: Naggaroth Night equivalents · Dioxazine Purple equivalents