ΔE 7.8, close: similar, with a visible difference side by side. Pure Blue is a little lighter, more saturated than Caledor Sky.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Pure Blue is a little lighter, more saturated than Caledor Sky.
The same difference applies the other way round: Caledor Sky is a little darker, 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 Caledor Sky on the colour wheel See Pure Blue on the colour wheel
All matches: Caledor Sky equivalents · Pure Blue equivalents