ΔE 26.3, loose: different enough that you should pick on purpose. Elfic Blue is a little lighter, much more saturated than Grey Goose.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 26). Elfic Blue is a little lighter, much more saturated than Grey Goose.
The same difference applies the other way round: Grey Goose is a little darker, 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 Grey Goose on the colour wheel See Elfic Blue on the colour wheel
All matches: Grey Goose equivalents · Elfic Blue equivalents