Ultramarine Blue vs Kantor Blue

How close are they?

ΔE 12.1, fair: the same colour family, but not a straight swap. Kantor Blue is noticeably darker, warmer than Ultramarine Blue.

Can I use Kantor Blue instead of Ultramarine Blue?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Kantor Blue is noticeably darker, warmer than Ultramarine Blue.

Can I use Ultramarine Blue instead of Kantor Blue?

The same difference applies the other way round: Ultramarine Blue is noticeably lighter, 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.