ΔE 18.5, loose: different enough that you should pick on purpose. Storm Blue is a little darker, much more saturated than Fairy Blood.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Storm Blue is a little darker, much more saturated than Fairy Blood.
The same difference applies the other way round: Fairy Blood is a little lighter, much more muted.
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 Fairy Blood on the colour wheel See Storm Blue on the colour wheel
All matches: Fairy Blood equivalents · Storm Blue equivalents