ΔE 12.1, fair: the same colour family, but not a straight swap. Flat Blue is a little darker, warmer than Azurite Hue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Flat Blue is a little darker, warmer than Azurite Hue.
The same difference applies the other way round: Azurite Hue 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 Azurite Hue on the colour wheel See Flat Blue on the colour wheel
All matches: Azurite Hue equivalents · Flat Blue equivalents