ΔE 11.3, fair: the same colour family, but not a straight swap. Celestial Violet is a little lighter, warmer than Sparkling Amethyst.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Celestial Violet is a little lighter, warmer than Sparkling Amethyst.
The same difference applies the other way round: Sparkling Amethyst is a little darker, 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 Sparkling Amethyst on the colour wheel See Celestial Violet on the colour wheel
All matches: Sparkling Amethyst equivalents · Celestial Violet equivalents