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