ΔE 18.7, loose: different enough that you should pick on purpose. Plague Brown is noticeably lighter, much more saturated than Sahara Yellow.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Plague Brown is noticeably lighter, much more saturated than Sahara Yellow.
The same difference applies the other way round: Sahara Yellow is noticeably darker, much 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.
See Sahara Yellow on the colour wheel See Plague Brown on the colour wheel
All matches: Sahara Yellow equivalents · Plague Brown equivalents