ΔE 11.8, fair: the same colour family, but not a straight swap. Azure is more muted, warmer than Primary Cyan.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Azure is more muted, warmer than Primary Cyan.
The same difference applies the other way round: Primary Cyan 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 Primary Cyan on the colour wheel See Azure on the colour wheel
All matches: Primary Cyan equivalents · Azure equivalents