Alien Purple vs Ultramarine

How close are they?

ΔE 14.6, fair: the same colour family, but not a straight swap. Ultramarine is more saturated, cooler than Alien Purple.

Can I use Ultramarine instead of Alien Purple?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Ultramarine is more saturated, cooler than Alien Purple.

Can I use Alien Purple instead of Ultramarine?

The same difference applies the other way round: Alien Purple is more muted, 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.