Hanpu Beige vs Underhive Ash

How close are they?

ΔE 8.1, close: similar, with a visible difference side by side. Underhive Ash is a little darker, more muted, cooler than Hanpu Beige.

Can I use Underhive Ash instead of Hanpu Beige?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Underhive Ash is a little darker, more muted, cooler than Hanpu Beige.

Can I use Hanpu Beige instead of Underhive Ash?

The same difference applies the other way round: Hanpu Beige is a little lighter, more saturated, 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.