ΔE 7.6, close: similar, with a visible difference side by side. Stormhost Silver is a little lighter than Polished Silver.
Can I use Stormhost Silver instead of Polished Silver?
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Stormhost Silver is a little lighter than Polished Silver.
Can I use Polished Silver instead of Stormhost Silver?
The same difference applies the other way round: Polished Silver 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.