ΔE 5.1, very close: most people won’t see a difference side by side. Iridescent Silver (Fine) is more muted than Great Hall Grey. They are different kinds of paint: Army Painter Great Hall Grey is an opaque base/layer paint and Golden Iridescent Silver (Fine) is a pearl paint, so they won’t behave the same on the model even where the colour is close.
Yes, for most jobs. Very close match (ΔE 5). Iridescent Silver (Fine) is more muted than Great Hall Grey. They are different kinds of paint.
The same difference applies the other way round: Great Hall Grey is more saturated.
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 Great Hall Grey on the colour wheel See Iridescent Silver (Fine) on the colour wheel
All matches: Great Hall Grey equivalents · Iridescent Silver (Fine) equivalents