ΔE 11.4, fair: the same colour family, but not a straight swap. Barbarian Skin is a little darker, more saturated, cooler than Eldar Flesh.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Barbarian Skin is a little darker, more saturated, cooler than Eldar Flesh.
The same difference applies the other way round: Eldar Flesh 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 Eldar Flesh on the colour wheel See Barbarian Skin on the colour wheel
All matches: Eldar Flesh equivalents · Barbarian Skin equivalents