Blue Black vs Dark Prussian Blue

How close are they?

ΔE 12.0, fair: the same colour family, but not a straight swap. Dark Prussian Blue is a little lighter, more saturated, warmer than Blue Black.

Can I use Dark Prussian Blue instead of Blue Black?

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

Can I use Blue Black instead of Dark Prussian Blue?

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