Dark Hot Pink vs Witch Purple

How close are they?

ΔE 16.3, loose: different enough that you should pick on purpose. Witch Purple is a little lighter, more saturated, cooler than Dark Hot Pink.

Can I use Witch Purple instead of Dark Hot Pink?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Witch Purple is a little lighter, more saturated, cooler than Dark Hot Pink.

Can I use Dark Hot Pink instead of Witch Purple?

The same difference applies the other way round: Dark Hot Pink is a little darker, more muted, 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.