Deep Blue vs Prussian Blue

How close are they?

ΔE 5.4, very close: most people won’t see a difference side by side. Prussian Blue is a little lighter, cooler than Deep Blue.

Can I use Prussian Blue instead of Deep Blue?

Yes, for most jobs. Very close match (ΔE 5). Prussian Blue is a little lighter, cooler than Deep Blue.

Can I use Deep Blue instead of Prussian Blue?

The same difference applies the other way round: Deep Blue is a little 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.