Arianrhod Blue vs Blue Violet

How close are they?

ΔE 8.6, close: similar, with a visible difference side by side. Blue Violet is more muted than Arianrhod Blue.

Can I use Blue Violet instead of Arianrhod Blue?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Blue Violet is more muted than Arianrhod Blue.

Can I use Arianrhod Blue instead of Blue Violet?

The same difference applies the other way round: Arianrhod Blue is more saturated.

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.