ΔE 10.3, fair: the same colour family, but not a straight swap. Amethyst Purple is a little darker, more saturated than Kunzite Alchemy.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Amethyst Purple is a little darker, more saturated than Kunzite Alchemy.
The same difference applies the other way round: Kunzite Alchemy is a little lighter, more muted.
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.
See Kunzite Alchemy on the colour wheel See Amethyst Purple on the colour wheel
All matches: Kunzite Alchemy equivalents · Amethyst Purple equivalents