ΔE 10.4, fair: the same colour family, but not a straight swap. Plague Brown is a little lighter, cooler than Arrakis Brown.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Plague Brown is a little lighter, cooler than Arrakis Brown.
The same difference applies the other way round: Arrakis Brown is a little darker, 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 Arrakis Brown on the colour wheel See Plague Brown on the colour wheel
All matches: Arrakis Brown equivalents · Plague Brown equivalents