ΔE 52.8, loose: different enough that you should pick on purpose. Fluorescent Magenta is more saturated, cooler than Red Ecstasy.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 53). Fluorescent Magenta is more saturated, cooler than Red Ecstasy.
The same difference applies the other way round: Red Ecstasy is more muted, warmer.
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 Red Ecstasy on the colour wheel See Fluorescent Magenta on the colour wheel
All matches: Red Ecstasy equivalents · Fluorescent Magenta equivalents