Impish Rouge vs Dark Hot Pink

How close are they?

ΔE 19.7, loose: different enough that you should pick on purpose. Dark Hot Pink is noticeably darker, warmer than Impish Rouge.

Can I use Dark Hot Pink instead of Impish Rouge?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Dark Hot Pink is noticeably darker, warmer than Impish Rouge.

Can I use Impish Rouge instead of Dark Hot Pink?

The same difference applies the other way round: Impish Rouge is noticeably lighter, 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.