ΔE 4.5, very close: most people won’t see a difference side by side. Valhallan Blizzard is a little lighter than Fog Grey. They are different kinds of paint: AMMO by Mig Fog Grey is an opaque base/layer paint and Citadel Valhallan Blizzard is a technical paint or medium, 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). Valhallan Blizzard is a little lighter than Fog Grey. They are different kinds of paint.
The same difference applies the other way round: Fog 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 Fog Grey on the colour wheel See Valhallan Blizzard on the colour wheel
All matches: Fog Grey equivalents · Valhallan Blizzard equivalents