Copper vs Talos Bronze

How close are they?

ΔE 26.4, loose: different enough that you should pick on purpose. Talos Bronze is noticeably darker, warmer than Copper.

Can I use Talos Bronze instead of Copper?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 26). Talos Bronze is noticeably darker, warmer than Copper.

Can I use Copper instead of Talos Bronze?

The same difference applies the other way round: Copper 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.