Dark Warm Flesh vs Dark Sand

How close are they?

ΔE 19.2, loose: different enough that you should pick on purpose. Dark Sand is noticeably darker, more muted, cooler than Dark Warm Flesh.

Can I use Dark Sand instead of Dark Warm Flesh?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Dark Sand is noticeably darker, more muted, cooler than Dark Warm Flesh.

Can I use Dark Warm Flesh instead of Dark Sand?

The same difference applies the other way round: Dark Warm Flesh is noticeably lighter, more saturated, 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.