ΔE 13.7, fair: the same colour family, but not a straight swap. UK Azure Blue is noticeably lighter, warmer than Blue Gray.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). UK Azure Blue is noticeably lighter, warmer than Blue Gray.
The same difference applies the other way round: Blue Gray is noticeably darker, 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 Blue Gray on the colour wheel See UK Azure Blue on the colour wheel
All matches: Blue Gray equivalents · UK Azure Blue equivalents