ΔE 12.1, fair: the same colour family, but not a straight swap. Purple is a little lighter, more saturated, warmer than Amethyst Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Purple is a little lighter, more saturated, warmer than Amethyst Blue.
The same difference applies the other way round: Amethyst Blue is a little darker, more muted, cooler.
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 Amethyst Blue on the colour wheel See Purple on the colour wheel
All matches: Amethyst Blue equivalents · Purple equivalents