ΔE 9.5, close: similar, with a visible difference side by side. IJN Gray is a little darker, more muted, warmer than Stormfang.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). IJN Gray is a little darker, more muted, warmer than Stormfang.
The same difference applies the other way round: Stormfang is a little lighter, more saturated, cooler.
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 IJN Gray on the colour wheel
All matches: Stormfang equivalents · IJN Gray equivalents