Arid Earth vs Sickly Skin

How close are they?

ΔE 8.2, close: similar, with a visible difference side by side. Sickly Skin is a little darker, cooler than Arid Earth.

Can I use Sickly Skin instead of Arid Earth?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Sickly Skin is a little darker, cooler than Arid Earth.

Can I use Arid Earth instead of Sickly Skin?

The same difference applies the other way round: Arid Earth is a little lighter, 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.