Dark Umber vs Olive Brown

How close are they?

ΔE 12.5, fair: the same colour family, but not a straight swap. Olive Brown is a little lighter, more muted than Dark Umber.

Can I use Olive Brown instead of Dark Umber?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Olive Brown is a little lighter, more muted than Dark Umber.

Can I use Dark Umber instead of Olive Brown?

The same difference applies the other way round: Dark Umber is a little darker, 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.