ΔE 13.7, fair: the same colour family, but not a straight swap. Icy Grey is a little lighter, much more muted than Stormfang.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Icy Grey is a little lighter, much more muted than Stormfang.
The same difference applies the other way round: Stormfang is a little darker, much more saturated.
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 Stormfang on the colour wheel See Icy Grey on the colour wheel
All matches: Stormfang equivalents · Icy Grey equivalents