ΔE 13.8, fair: the same colour family, but not a straight swap. Nightmare Purple is a little darker, cooler than Phoenician Purple.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Nightmare Purple is a little darker, cooler than Phoenician Purple.
The same difference applies the other way round: Phoenician Purple is a little lighter, 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 Phoenician Purple on the colour wheel See Nightmare Purple on the colour wheel
All matches: Phoenician Purple equivalents · Nightmare Purple equivalents