ΔE 10.0, fair: the same colour family, but not a straight swap. Interior Grey Green is a little darker, cooler than Underhive Ash.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Interior Grey Green is a little darker, cooler than Underhive Ash.
The same difference applies the other way round: Underhive Ash 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.
See Underhive Ash on the colour wheel See Interior Grey Green on the colour wheel
All matches: Underhive Ash equivalents · Interior Grey Green equivalents