Kantor Blue vs Dioxazine Purple

How close are they?

ΔE 18.5, loose: different enough that you should pick on purpose. Dioxazine Purple is a little darker, more muted, warmer than Kantor Blue.

Can I use Dioxazine Purple instead of Kantor Blue?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Dioxazine Purple is a little darker, more muted, warmer than Kantor Blue.

Can I use Kantor Blue instead of Dioxazine Purple?

The same difference applies the other way round: Kantor Blue is a little lighter, more saturated, 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.