Deep Cyan vs Lothern Blue

How close are they?

ΔE 13.2, fair: the same colour family, but not a straight swap. Lothern Blue is noticeably darker, more muted than Deep Cyan.

Can I use Lothern Blue instead of Deep Cyan?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Lothern Blue is noticeably darker, more muted than Deep Cyan.

Can I use Deep Cyan instead of Lothern Blue?

The same difference applies the other way round: Deep Cyan is noticeably lighter, more saturated.

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.