ΔE 12.7, fair: the same colour family, but not a straight swap. Ancient Copper is noticeably darker, more saturated than Gold.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Ancient Copper is noticeably darker, more saturated than Gold.
The same difference applies the other way round: Gold is noticeably lighter, 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.
See Gold on the colour wheel See Ancient Copper on the colour wheel
All matches: Gold equivalents · Ancient Copper equivalents