Black Metal vs Bronze

How close are they?

ΔE 17.1, loose: different enough that you should pick on purpose. Bronze is a little lighter, much more saturated than Black Metal.

Can I use Bronze instead of Black Metal?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Bronze is a little lighter, much more saturated than Black Metal.

Can I use Black Metal instead of Bronze?

The same difference applies the other way round: Black Metal is a little darker, much more muted.

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.