Dark Purple vs Dark Blue

How close are they?

ΔE 10.6, fair: the same colour family, but not a straight swap. Dark Blue is a little lighter, cooler than Dark Purple.

Can I use Dark Blue instead of Dark Purple?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Dark Blue is a little lighter, cooler than Dark Purple.

Can I use Dark Purple instead of Dark Blue?

The same difference applies the other way round: Dark Purple 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.