Fairy Dust vs White Alchemy

How close are they?

ΔE 9.4, close: similar, with a visible difference side by side. White Alchemy is a little lighter, more muted than Fairy Dust.

Can I use White Alchemy instead of Fairy Dust?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). White Alchemy is a little lighter, more muted than Fairy Dust.

Can I use Fairy Dust instead of White Alchemy?

The same difference applies the other way round: Fairy Dust is a little darker, 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.