ΔE 13.4, fair: the same colour family, but not a straight swap. Terran Khaki is a little lighter, more muted, warmer than Necrotic Flesh.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Terran Khaki is a little lighter, more muted, warmer than Necrotic Flesh.
The same difference applies the other way round: Necrotic Flesh is a little darker, 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 Necrotic Flesh on the colour wheel See Terran Khaki on the colour wheel
All matches: Necrotic Flesh equivalents · Terran Khaki equivalents