Weathered Skin vs Orcish Dermis

How close are they?

ΔE 7.1, close: similar, with a visible difference side by side. Orcish Dermis is more saturated, cooler than Weathered Skin.

Can I use Orcish Dermis instead of Weathered Skin?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Orcish Dermis is more saturated, cooler than Weathered Skin.

Can I use Weathered Skin instead of Orcish Dermis?

The same difference applies the other way round: Weathered Skin is more muted, warmer.

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.