Purple Flesh vs Lustful Purple

How close are they?

ΔE 21.7, loose: different enough that you should pick on purpose. Lustful Purple is noticeably lighter, cooler than Purple Flesh.

Can I use Lustful Purple instead of Purple Flesh?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 22). Lustful Purple is noticeably lighter, cooler than Purple Flesh.

Can I use Purple Flesh instead of Lustful Purple?

The same difference applies the other way round: Purple Flesh is noticeably darker, 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.