ΔE 11.8, fair: the same colour family, but not a straight swap. Purple People Eater is noticeably darker than Cultist Purple.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Purple People Eater is noticeably darker than Cultist Purple.
The same difference applies the other way round: Cultist Purple is noticeably lighter.
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 Cultist Purple on the colour wheel See Purple People Eater on the colour wheel
All matches: Cultist Purple equivalents · Purple People Eater equivalents