ΔE 14.1, fair: the same colour family, but not a straight swap. Grey Brown is more muted, warmer than Gangrene.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Grey Brown is more muted, warmer than Gangrene.
The same difference applies the other way round: Gangrene 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.
See Gangrene on the colour wheel See Grey Brown on the colour wheel
All matches: Gangrene equivalents · Grey Brown equivalents