Altdorf Guard Blue vs Primary Cyan

How close are they?

ΔE 14.0, fair: the same colour family, but not a straight swap. Primary Cyan is noticeably lighter, cooler than Altdorf Guard Blue.

Can I use Primary Cyan instead of Altdorf Guard Blue?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Primary Cyan is noticeably lighter, cooler than Altdorf Guard Blue.

Can I use Altdorf Guard Blue instead of Primary Cyan?

The same difference applies the other way round: Altdorf Guard Blue is noticeably darker, 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.