Light Bronze vs Arcane Gold

How close are they?

ΔE 18.8, loose: different enough that you should pick on purpose. Arcane Gold is noticeably lighter, more saturated, cooler than Light Bronze.

Can I use Arcane Gold instead of Light Bronze?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Arcane Gold is noticeably lighter, more saturated, cooler than Light Bronze.

Can I use Light Bronze instead of Arcane Gold?

The same difference applies the other way round: Light Bronze is noticeably darker, more muted, 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.