Dust vs Ushabti Bone

How close are they?

ΔE 8.9, close: similar, with a visible difference side by side. Ushabti Bone is a little lighter, cooler than Dust.

Can I use Ushabti Bone instead of Dust?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Ushabti Bone is a little lighter, cooler than Dust.

Can I use Dust instead of Ushabti Bone?

The same difference applies the other way round: Dust is a little darker, 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.