Primary Cyan vs Imperial Blue

How close are they?

ΔE 12.5, fair: the same colour family, but not a straight swap. Imperial Blue is a little darker, more muted, warmer than Primary Cyan.

Can I use Imperial Blue instead of Primary Cyan?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Imperial Blue is a little darker, more muted, warmer than Primary Cyan.

Can I use Primary Cyan instead of Imperial Blue?

The same difference applies the other way round: Primary Cyan is a little lighter, more saturated, 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.