Alien Purple vs Imperium Blue

How close are they?

ΔE 14.7, fair: the same colour family, but not a straight swap. Imperium Blue is noticeably darker, more saturated, cooler than Alien Purple.

Can I use Imperium Blue instead of Alien Purple?

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

Can I use Alien Purple instead of Imperium Blue?

The same difference applies the other way round: Alien Purple is noticeably lighter, 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.