ΔE 6.7, close: similar, with a visible difference side by side. A-28M Greyish Blue is a little lighter, warmer than Light Aircraft Gray BS381C/627.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). A-28M Greyish Blue is a little lighter, warmer than Light Aircraft Gray BS381C/627.
The same difference applies the other way round: Light Aircraft Gray BS381C/627 is a little darker, cooler.
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 Light Aircraft Gray BS381C/627 on the colour wheel See A-28M Greyish Blue on the colour wheel
All matches: Light Aircraft Gray BS381C/627 equivalents · A-28M Greyish Blue equivalents