ΔE 5.7, very close: most people won’t see a difference side by side. Carbon Black is a little lighter than Onyx Skin. They are different kinds of paint: Army Painter Onyx Skin is an opaque base/layer paint and Golden Carbon Black is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Yes, for most jobs. Very close match (ΔE 6). Carbon Black is a little lighter than Onyx Skin. They are different kinds of paint.
The same difference applies the other way round: Onyx Skin 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 Onyx Skin on the colour wheel See Carbon Black on the colour wheel
All matches: Onyx Skin equivalents · Carbon Black equivalents