Fluorescent Pink vs Fluorescent Magenta

How close are they?

ΔE 15.9, loose: different enough that you should pick on purpose. Fluorescent Magenta is a little darker, more saturated than Fluorescent Pink.

Can I use Fluorescent Magenta instead of Fluorescent Pink?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Fluorescent Magenta is a little darker, more saturated than Fluorescent Pink.

Can I use Fluorescent Pink instead of Fluorescent Magenta?

The same difference applies the other way round: Fluorescent Pink is a little lighter, 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.