Witchbane Plum vs Pink

How close are they?

ΔE 18.9, loose: different enough that you should pick on purpose. Pink is noticeably lighter, more saturated than Witchbane Plum.

Can I use Pink instead of Witchbane Plum?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Pink is noticeably lighter, more saturated than Witchbane Plum.

Can I use Witchbane Plum instead of Pink?

The same difference applies the other way round: Witchbane Plum is noticeably darker, more muted.

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.