ΔE 10.2, fair: the same colour family, but not a straight swap. Brown Beast Ink is a little darker, more saturated, warmer than Dark Skin Shade. They are different kinds of paint: Army Painter Dark Skin Shade is a wash/shade and Nocturna Models Brown Beast Ink is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Brown Beast Ink is a little darker, more saturated, warmer than Dark Skin Shade. They are different kinds of paint.
The same difference applies the other way round: Dark Skin Shade is a little lighter, more muted, cooler.
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 Dark Skin Shade on the colour wheel See Brown Beast Ink on the colour wheel
All matches: Dark Skin Shade equivalents · Brown Beast Ink equivalents