Blood Thorn vs Dark Hot Pink

How close are they?

ΔE 17.6, loose: different enough that you should pick on purpose. Dark Hot Pink is a little lighter, cooler than Blood Thorn.

Can I use Dark Hot Pink instead of Blood Thorn?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Dark Hot Pink is a little lighter, cooler than Blood Thorn.

Can I use Blood Thorn instead of Dark Hot Pink?

The same difference applies the other way round: Blood Thorn is a little 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.