Chaos Bronze vs Rusty Metal

How close are they?

ΔE 15.0, loose: different enough that you should pick on purpose. Rusty Metal is noticeably darker, warmer than Chaos Bronze.

Can I use Rusty Metal instead of Chaos Bronze?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Rusty Metal is noticeably darker, warmer than Chaos Bronze.

Can I use Chaos Bronze instead of Rusty Metal?

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