ΔE 10.0, close: similar, with a visible difference side by side. Hammered Copper is a little darker, more saturated than Stormhost Silver.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Hammered Copper is a little darker, more saturated than Stormhost Silver.
The same difference applies the other way round: Stormhost Silver is a little lighter, more muted.
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 Stormhost Silver on the colour wheel See Hammered Copper on the colour wheel
All matches: Stormhost Silver equivalents · Hammered Copper equivalents