ΔE 17.1, loose: different enough that you should pick on purpose. Quinacridone Magenta is much more muted, warmer than Kakophoni Purple. They are different kinds of paint: Citadel Kakophoni Purple is an opaque base/layer paint and Golden Quinacridone Magenta is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Quinacridone Magenta is much more muted, warmer than Kakophoni Purple. They are different kinds of paint.
The same difference applies the other way round: Kakophoni Purple is much more saturated, 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 Kakophoni Purple on the colour wheel See Quinacridone Magenta on the colour wheel
All matches: Kakophoni Purple equivalents · Quinacridone Magenta equivalents