ΔE 20.7, loose: different enough that you should pick on purpose. Fluorescent Red is a little darker, much more saturated, warmer than Fluorescent Magenta.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Fluorescent Red is a little darker, much more saturated, warmer than Fluorescent Magenta.
The same difference applies the other way round: Fluorescent Magenta is a little lighter, much more muted, 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 Fluorescent Red on the colour wheel
All matches: Fluorescent Magenta equivalents · Fluorescent Red equivalents