Witchbane Plum vs Liche Purple

How close are they?

ΔE 16.3, loose: different enough that you should pick on purpose. Liche Purple is a little darker, more muted, cooler than Witchbane Plum.

Can I use Liche Purple instead of Witchbane Plum?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Liche Purple is a little darker, more muted, cooler than Witchbane Plum.

Can I use Witchbane Plum instead of Liche Purple?

The same difference applies the other way round: Witchbane Plum is a little 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.