Underhive Ash vs Kobold Grey

How close are they?

ΔE 11.7, fair: the same colour family, but not a straight swap. Kobold Grey is noticeably darker, cooler than Underhive Ash.

Can I use Kobold Grey instead of Underhive Ash?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Kobold Grey is noticeably darker, cooler than Underhive Ash.

Can I use Underhive Ash instead of Kobold Grey?

The same difference applies the other way round: Underhive Ash is noticeably 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.