Brazen Copper vs Iron Fist

How close are they?

ΔE 33.0, loose: different enough that you should pick on purpose. Iron Fist is noticeably lighter, much more muted than Brazen Copper.

Can I use Iron Fist instead of Brazen Copper?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 33). Iron Fist is noticeably lighter, much more muted than Brazen Copper.

Can I use Brazen Copper instead of Iron Fist?

The same difference applies the other way round: Brazen Copper is noticeably darker, 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.