ΔE 10.5, fair: the same colour family, but not a straight swap. Prussian Blue is a little darker, more muted, cooler than Amethyst Rayne.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Prussian Blue is a little darker, more muted, cooler than Amethyst Rayne.
The same difference applies the other way round: Amethyst Rayne is a little lighter, more saturated, 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.
See Amethyst Rayne on the colour wheel See Prussian Blue on the colour wheel
All matches: Amethyst Rayne equivalents · Prussian Blue equivalents