ΔE 15.0, loose: different enough that you should pick on purpose. Light Blue (Luftwaffe) is a little lighter, much more saturated than Administratum Grey.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Light Blue (Luftwaffe) is a little lighter, much more saturated than Administratum Grey.
The same difference applies the other way round: Administratum Grey 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 Administratum Grey on the colour wheel See Light Blue (Luftwaffe) on the colour wheel
All matches: Administratum Grey equivalents · Light Blue (Luftwaffe) equivalents