ΔE 25.4, loose: different enough that you should pick on purpose. Clear Magenta is much more saturated than Pink Horror. They are different kinds of paint: Citadel Pink Horror is an opaque base/layer paint and Reaper Clear Magenta is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 25). Clear Magenta is much more saturated than Pink Horror. They are different kinds of paint.
The same difference applies the other way round: Pink Horror is much 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.
See Pink Horror on the colour wheel See Clear Magenta on the colour wheel
All matches: Pink Horror equivalents · Clear Magenta equivalents