ΔE 13.8, fair: the same colour family, but not a straight swap. Dark Copper is more saturated, warmer than Canoptek Alloy.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Dark Copper is more saturated, warmer than Canoptek Alloy.
The same difference applies the other way round: Canoptek Alloy is more muted, cooler.
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 Canoptek Alloy on the colour wheel See Dark Copper on the colour wheel
All matches: Canoptek Alloy equivalents · Dark Copper equivalents