ΔE 12.2, fair: the same colour family, but not a straight swap. Burnt Umber Light is more muted, warmer than Mournfang Brown.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Burnt Umber Light is more muted, warmer than Mournfang Brown.
The same difference applies the other way round: Mournfang Brown is more saturated, cooler.
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 Mournfang Brown on the colour wheel See Burnt Umber Light on the colour wheel
All matches: Mournfang Brown equivalents · Burnt Umber Light equivalents