ΔE 9.2, close: similar, with a visible difference side by side. Azure is a little darker, warmer than Medium Blue.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Azure is a little darker, warmer than Medium Blue.
The same difference applies the other way round: Medium Blue is a little lighter, 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 Medium Blue on the colour wheel See Azure on the colour wheel
All matches: Medium Blue equivalents · Azure equivalents