ΔE 12.7, fair: the same colour family, but not a straight swap. Elf Skin Tone is noticeably lighter than Idrian Flesh.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Elf Skin Tone is noticeably lighter than Idrian Flesh.
The same difference applies the other way round: Idrian Flesh is noticeably darker.
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 Idrian Flesh on the colour wheel See Elf Skin Tone on the colour wheel
All matches: Idrian Flesh equivalents · Elf Skin Tone equivalents