ΔE 13.1, fair: the same colour family, but not a straight swap. Dark Flesh Tone is a little lighter, more muted, cooler than Brown Skin.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Dark Flesh Tone is a little lighter, more muted, cooler than Brown Skin.
The same difference applies the other way round: Brown Skin is a little darker, more saturated, 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 Brown Skin on the colour wheel See Dark Flesh Tone on the colour wheel
All matches: Brown Skin equivalents · Dark Flesh Tone equivalents