Mid Brown vs Petroleum Brown Wash

How close are they?

ΔE 15.9, loose: different enough that you should pick on purpose. Petroleum Brown Wash is a little darker, much more muted than Mid Brown.

Can I use Petroleum Brown Wash instead of Mid Brown?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Petroleum Brown Wash is a little darker, much more muted than Mid Brown.

Can I use Mid Brown instead of Petroleum Brown Wash?

The same difference applies the other way round: Mid Brown is a little lighter, much 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.