ΔE 10.8, fair: the same colour family, but not a straight swap. Kislev Flesh is a little lighter, more muted, warmer than Agate Skin.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Kislev Flesh is a little lighter, more muted, warmer than Agate Skin.
The same difference applies the other way round: Agate Skin is a little darker, 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 Agate Skin on the colour wheel See Kislev Flesh on the colour wheel
All matches: Agate Skin equivalents · Kislev Flesh equivalents