ΔE 20.2, loose: different enough that you should pick on purpose. Magic Blue is noticeably darker, much more saturated, cooler than Space Wolves Grey.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Magic Blue is noticeably darker, much more saturated, cooler than Space Wolves Grey.
The same difference applies the other way round: Space Wolves Grey is noticeably lighter, much 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 Space Wolves Grey on the colour wheel See Magic Blue on the colour wheel
All matches: Space Wolves Grey equivalents · Magic Blue equivalents