ΔE 10.3, fair: the same colour family, but not a straight swap. Plague Brown is noticeably darker than Volcanic Yellow.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Plague Brown is noticeably darker than Volcanic Yellow.
The same difference applies the other way round: Volcanic Yellow is noticeably lighter.
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 Volcanic Yellow on the colour wheel See Plague Brown on the colour wheel
All matches: Volcanic Yellow equivalents · Plague Brown equivalents