ΔE 14.0, fair: the same colour family, but not a straight swap. Elf Skin Tone is a little darker, more saturated, cooler than Blackert Brown.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Elf Skin Tone is a little darker, more saturated, cooler than Blackert Brown.
The same difference applies the other way round: Blackert Brown is a little lighter, more muted, 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 Blackert Brown on the colour wheel See Elf Skin Tone on the colour wheel
All matches: Blackert Brown equivalents · Elf Skin Tone equivalents