ΔE 8.0, close: similar, with a visible difference side by side. Iridescent Copper (Coarse) is a little lighter, more saturated, cooler than True Copper. They are different kinds of paint: Army Painter True Copper is a metallic and Golden Iridescent Copper (Coarse) is a pearl paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Iridescent Copper (Coarse) is a little lighter, more saturated, cooler than True Copper. They are different kinds of paint.
The same difference applies the other way round: True Copper is a little darker, more muted, warmer.
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 True Copper on the colour wheel See Iridescent Copper (Coarse) on the colour wheel
All matches: True Copper equivalents · Iridescent Copper (Coarse) equivalents