ΔE 15.4, loose: different enough that you should pick on purpose. Magenta is noticeably darker, more muted than Pink Horror.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Magenta is noticeably darker, more muted than Pink Horror.
The same difference applies the other way round: Pink Horror is noticeably lighter, more saturated.
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.
See Pink Horror on the colour wheel See Magenta on the colour wheel
All matches: Pink Horror equivalents · Magenta equivalents