Lothern Blue vs Primary Blue

How close are they?

ΔE 11.8, fair: the same colour family, but not a straight swap. Primary Blue is a little lighter, more saturated, cooler than Lothern Blue.

Can I use Primary Blue instead of Lothern Blue?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Primary Blue is a little lighter, more saturated, cooler than Lothern Blue.

Can I use Lothern Blue instead of Primary Blue?

The same difference applies the other way round: Lothern Blue is a little darker, more muted, 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.