ΔE 19.1, loose: different enough that you should pick on purpose. Copper is a little lighter, more saturated than Golden Armour.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Copper is a little lighter, more saturated than Golden Armour.
The same difference applies the other way round: Golden Armour is a little darker, 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 Golden Armour on the colour wheel See Copper on the colour wheel
All matches: Golden Armour equivalents · Copper equivalents