ΔE 7.3, close: similar, with a visible difference side by side. Nuln Oil is a little lighter than Burnt Umber INK. They are different kinds of paint: AK Interactive Burnt Umber INK is an ink, glaze or transparent paint and Citadel Nuln Oil is a wash/shade, 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 7). Nuln Oil is a little lighter than Burnt Umber INK. They are different kinds of paint.
The same difference applies the other way round: Burnt Umber INK 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 Burnt Umber INK on the colour wheel See Nuln Oil on the colour wheel
All matches: Burnt Umber INK equivalents · Nuln Oil equivalents