ΔE 45.7, loose: different enough that you should pick on purpose. Fluorescent Yellow is noticeably lighter, more saturated, cooler than Fluorescent Orange.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 46). Fluorescent Yellow is noticeably lighter, more saturated, cooler than Fluorescent Orange.
The same difference applies the other way round: Fluorescent Orange is noticeably darker, 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 Fluorescent Orange on the colour wheel See Fluorescent Yellow on the colour wheel
All matches: Fluorescent Orange equivalents · Fluorescent Yellow equivalents