Broodmother Purple vs Deep Blue

How close are they?

ΔE 6.3, close: similar, with a visible difference side by side. Deep Blue is a little lighter, cooler than Broodmother Purple.

Can I use Deep Blue instead of Broodmother Purple?

Usually, if you are not matching paint already on the model. Close match (ΔE 6). Deep Blue is a little lighter, cooler than Broodmother Purple.

Can I use Broodmother Purple instead of Deep Blue?

The same difference applies the other way round: Broodmother 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.