ΔE 13.8, fair: the same colour family, but not a straight swap. Dark Flesh Tone is more muted, cooler than Middle Brown.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Dark Flesh Tone is more muted, cooler than Middle Brown.
The same difference applies the other way round: Middle Brown is 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 Middle Brown on the colour wheel See Dark Flesh Tone on the colour wheel
All matches: Middle Brown equivalents · Dark Flesh Tone equivalents