ΔE 25.5, loose: different enough that you should pick on purpose. Iridescent Copper Light (Coarse) is more muted, warmer than Shin Gunto Gold. They are different kinds of paint: Army Painter Shin Gunto Gold is a metallic and Golden Iridescent Copper Light (Coarse) is a pearl paint, so they won’t behave the same on the model even where the colour is close.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 26). Iridescent Copper Light (Coarse) is more muted, warmer than Shin Gunto Gold. They are different kinds of paint.
The same difference applies the other way round: Shin Gunto Gold is more saturated, 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 Shin Gunto Gold on the colour wheel See Iridescent Copper Light (Coarse) on the colour wheel
All matches: Shin Gunto Gold equivalents · Iridescent Copper Light (Coarse) equivalents