English Field Brown vs Earth

How close are they?

ΔE 17.3, loose: different enough that you should pick on purpose. Earth is noticeably lighter, cooler than English Field Brown.

Can I use Earth instead of English Field Brown?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Earth is noticeably lighter, cooler than English Field Brown.

Can I use English Field Brown instead of Earth?

The same difference applies the other way round: English Field Brown is noticeably darker, warmer.

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.