ΔE 10.9, fair: the same colour family, but not a straight swap. True Copper is more saturated, warmer than Copper.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). True Copper is more saturated, warmer than Copper.
The same difference applies the other way round: Copper 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 Copper on the colour wheel See True Copper on the colour wheel
All matches: Copper equivalents · True Copper equivalents