ΔE 9.6, close: similar, with a visible difference side by side. Steel Blue is a little darker, more muted, warmer than Star Blue.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Steel Blue is a little darker, more muted, warmer than Star Blue.
The same difference applies the other way round: Star Blue is a little lighter, 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 Star Blue on the colour wheel See Steel Blue on the colour wheel
All matches: Star Blue equivalents · Steel Blue equivalents