ΔE 18.8, loose: different enough that you should pick on purpose. Sea Blue is noticeably darker, more saturated, cooler than Stormfang.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Sea Blue is noticeably darker, more saturated, cooler than Stormfang.
The same difference applies the other way round: Stormfang is noticeably lighter, more muted, warmer.
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 Sea Blue on the colour wheel
All matches: Stormfang equivalents · Sea Blue equivalents