Purple Vanity vs Mystic Blue

How close are they?

ΔE 18.0, loose: different enough that you should pick on purpose. Mystic Blue is a little lighter, more saturated, cooler than Purple Vanity.

Can I use Mystic Blue instead of Purple Vanity?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Mystic Blue is a little lighter, more saturated, cooler than Purple Vanity.

Can I use Purple Vanity instead of Mystic Blue?

The same difference applies the other way round: Purple Vanity is a little darker, 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.