ΔE 26.2, loose: different enough that you should pick on purpose. Dark Vermilion is noticeably darker, much more saturated, cooler than Khardic Flesh.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 26). Dark Vermilion is noticeably darker, much more saturated, cooler than Khardic Flesh.
The same difference applies the other way round: Khardic Flesh is noticeably lighter, much 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 Khardic Flesh on the colour wheel See Dark Vermilion on the colour wheel
All matches: Khardic Flesh equivalents · Dark Vermilion equivalents