Oak Brown vs Umbral Umber

How close are they?

ΔE 12.5, fair: the same colour family, but not a straight swap. Umbral Umber is noticeably darker, warmer than Oak Brown.

Can I use Umbral Umber instead of Oak Brown?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Umbral Umber is noticeably darker, warmer than Oak Brown.

Can I use Oak Brown instead of Umbral Umber?

The same difference applies the other way round: Oak Brown is noticeably lighter, 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.