ΔE 30.1, loose: different enough that you should pick on purpose. Arcane Gold is noticeably darker, much more muted than Copper Coin.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 30). Arcane Gold is noticeably darker, much more muted than Copper Coin.
The same difference applies the other way round: Copper Coin is noticeably lighter, 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.
See Copper Coin on the colour wheel See Arcane Gold on the colour wheel
All matches: Copper Coin equivalents · Arcane Gold equivalents