ΔE 7.1, close: similar, with a visible difference side by side. Infantry Blue is more muted, warmer than Steely Blue.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Infantry Blue is more muted, warmer than Steely Blue.
The same difference applies the other way round: Steely Blue is more saturated, 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 Steely Blue on the colour wheel See Infantry Blue on the colour wheel
All matches: Steely Blue equivalents · Infantry Blue equivalents