ΔE 6.8, close: similar, with a visible difference side by side. Elf Skin Tone is more muted, warmer than Khardic Flesh.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Elf Skin Tone is more muted, warmer than Khardic Flesh.
The same difference applies the other way round: Khardic Flesh is 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 Khardic Flesh on the colour wheel See Elf Skin Tone on the colour wheel
All matches: Khardic Flesh equivalents · Elf Skin Tone equivalents