ΔE 14.4, fair: the same colour family, but not a straight swap. UK Azure Blue is a little darker, cooler than Runic Purple.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). UK Azure Blue is a little darker, cooler than Runic Purple.
The same difference applies the other way round: Runic Purple is a little lighter, warmer.
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 Runic Purple on the colour wheel See UK Azure Blue on the colour wheel
All matches: Runic Purple equivalents · UK Azure Blue equivalents