Purple Flesh vs Elder Flower

How close are they?

ΔE 15.4, loose: different enough that you should pick on purpose. Elder Flower is a little darker, more saturated, warmer than Purple Flesh.

Can I use Elder Flower instead of Purple Flesh?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Elder Flower is a little darker, more saturated, warmer than Purple Flesh.

Can I use Purple Flesh instead of Elder Flower?

The same difference applies the other way round: Purple Flesh is a little lighter, more muted, 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.