ΔE 6.7, close: similar, with a visible difference side by side. Silver is a little darker than Mystic White.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Silver is a little darker than Mystic White.
The same difference applies the other way round: Mystic White 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 Mystic White on the colour wheel See Silver on the colour wheel
All matches: Mystic White equivalents · Silver equivalents