ΔE 13.7, fair: the same colour family, but not a straight swap. Copper (Metallic) is noticeably lighter, more muted than Golden Moon.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Copper (Metallic) is noticeably lighter, more muted than Golden Moon.
The same difference applies the other way round: Golden Moon is noticeably darker, 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 Golden Moon on the colour wheel See Copper (Metallic) on the colour wheel
All matches: Golden Moon equivalents · Copper (Metallic) equivalents