ΔE 10.3, fair: the same colour family, but not a straight swap. Dark Gunmetal is a little darker than Iridescent Pearl (Coarse). They are different kinds of paint: Golden Iridescent Pearl (Coarse) is a pearl paint and Vallejo Dark Gunmetal is a metallic, so they won’t behave the same on the model even where the colour is close.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Dark Gunmetal is a little darker than Iridescent Pearl (Coarse). They are different kinds of paint.
The same difference applies the other way round: Iridescent Pearl (Coarse) is a little lighter.
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 Iridescent Pearl (Coarse) on the colour wheel See Dark Gunmetal on the colour wheel
All matches: Iridescent Pearl (Coarse) equivalents · Dark Gunmetal equivalents