ΔE 5.8, very close: most people won’t see a difference side by side. Iridescent Stainless Steel (Coarse) is a little darker than Grey Knights Steel. They are different kinds of paint: Citadel Grey Knights Steel is a metallic and Golden Iridescent Stainless Steel (Coarse) 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 6). Iridescent Stainless Steel (Coarse) is a little darker than Grey Knights Steel. They are different kinds of paint.
The same difference applies the other way round: Grey Knights Steel 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 Grey Knights Steel on the colour wheel See Iridescent Stainless Steel (Coarse) on the colour wheel
All matches: Grey Knights Steel equivalents · Iridescent Stainless Steel (Coarse) equivalents