ΔE 4.6, very close: most people won’t see a difference side by side. Iridescent Silver (Fine) is a little lighter than Longbeard Grey. They are different kinds of paint: Citadel Longbeard 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 a little lighter than Longbeard Grey. They are different kinds of paint.
The same difference applies the other way round: Longbeard Grey is a little darker.
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 Longbeard Grey on the colour wheel See Iridescent Silver (Fine) on the colour wheel
All matches: Longbeard Grey equivalents · Iridescent Silver (Fine) equivalents