Onyx Skin vs Arbuckles Brown

How close are they?

ΔE 8.0, close: similar, with a visible difference side by side. Arbuckles Brown is a little darker, more saturated than Onyx Skin.

Can I use Arbuckles Brown instead of Onyx Skin?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Arbuckles Brown is a little darker, more saturated than Onyx Skin.

Can I use Onyx Skin instead of Arbuckles Brown?

The same difference applies the other way round: Onyx Skin is a little lighter, 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.