ΔE 12.4, fair: the same colour family, but not a straight swap. Malefic Flesh is a little lighter, cooler than Graveyard Earth.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Malefic Flesh is a little lighter, cooler than Graveyard Earth.
The same difference applies the other way round: Graveyard Earth 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.
See Graveyard Earth on the colour wheel See Malefic Flesh on the colour wheel
All matches: Graveyard Earth equivalents · Malefic Flesh equivalents