ΔE 11.6, fair: the same colour family, but not a straight swap. Eldar Flesh is a little darker, more muted, warmer than Gnome Skin.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Eldar Flesh is a little darker, more muted, warmer than Gnome Skin.
The same difference applies the other way round: Gnome Skin is a little lighter, 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 Gnome Skin on the colour wheel See Eldar Flesh on the colour wheel
All matches: Gnome Skin equivalents · Eldar Flesh equivalents