Nightroot Shade vs Petroleum Brown Wash

How close are they?

ΔE 26.0, loose: different enough that you should pick on purpose. Petroleum Brown Wash is a little darker, warmer than Nightroot Shade.

Can I use Petroleum Brown Wash instead of Nightroot Shade?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 26). Petroleum Brown Wash is a little darker, warmer than Nightroot Shade.

Can I use Nightroot Shade instead of Petroleum Brown Wash?

The same difference applies the other way round: Nightroot Shade is a little 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.