Bronze vs Dark Emerald

How close are they?

ΔE 28.6, loose: different enough that you should pick on purpose. Dark Emerald is noticeably darker, cooler than Bronze.

Can I use Dark Emerald instead of Bronze?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 29). Dark Emerald is noticeably darker, cooler than Bronze.

Can I use Bronze instead of Dark Emerald?

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