ΔE 16.2, loose: different enough that you should pick on purpose. Plague Brown is more muted, cooler than Diarylide Yellow.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Plague Brown is more muted, cooler than Diarylide Yellow.
The same difference applies the other way round: Diarylide Yellow is more saturated, 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 Diarylide Yellow on the colour wheel See Plague Brown on the colour wheel
All matches: Diarylide Yellow equivalents · Plague Brown equivalents