Dust vs Dusty Skull

How close are they?

ΔE 6.9, close: similar, with a visible difference side by side. Dusty Skull is more muted, warmer than Dust.

Can I use Dusty Skull instead of Dust?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Dusty Skull is more muted, warmer than Dust.

Can I use Dust instead of Dusty Skull?

The same difference applies the other way round: Dust is more saturated, 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.