ΔE 19.1, loose: different enough that you should pick on purpose. Astorath Red is noticeably darker, warmer than Fluorescent Magenta. They are different kinds of paint: AK Interactive Fluorescent Magenta is a fluorescent or effect paint and Citadel Astorath Red is an opaque base/layer 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 19). Astorath Red is noticeably darker, warmer than Fluorescent Magenta. They are different kinds of paint.
The same difference applies the other way round: Fluorescent Magenta 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.
See Fluorescent Magenta on the colour wheel See Astorath Red on the colour wheel
All matches: Fluorescent Magenta equivalents · Astorath Red equivalents