Power Blue vs Andrea Blue

How close are they?

ΔE 9.3, close: similar, with a visible difference side by side. Andrea Blue is a little lighter, cooler than Power Blue.

Can I use Andrea Blue instead of Power Blue?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Andrea Blue is a little lighter, cooler than Power Blue.

Can I use Power Blue instead of Andrea Blue?

The same difference applies the other way round: Power Blue 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.