ΔE 10.6, fair: the same colour family, but not a straight swap. Brown is a little darker, more muted than Ruddy Terra.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Brown is a little darker, more muted than Ruddy Terra.
The same difference applies the other way round: Ruddy Terra is a little lighter, more saturated.
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 Ruddy Terra on the colour wheel See Brown on the colour wheel
All matches: Ruddy Terra equivalents · Brown equivalents