ΔE 11.9, fair: the same colour family, but not a straight swap. Black is a little darker, more muted than Umbral Umber.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Black is a little darker, more muted than Umbral Umber.
The same difference applies the other way round: Umbral Umber 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 Umbral Umber on the colour wheel See Black on the colour wheel
All matches: Umbral Umber equivalents · Black equivalents