ΔE 12.7, fair: the same colour family, but not a straight swap. Lothern Blue is more muted, cooler than Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Lothern Blue is more muted, cooler than Blue.
The same difference applies the other way round: Blue is more saturated, 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 Blue on the colour wheel See Lothern Blue on the colour wheel
All matches: Blue equivalents · Lothern Blue equivalents