ΔE 12.6, fair: the same colour family, but not a straight swap. Medium Magenta is a little darker, cooler than Pixie Pink. They are different kinds of paint: Army Painter Pixie Pink is an opaque base/layer paint and Golden Medium Magenta is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Medium Magenta is a little darker, cooler than Pixie Pink. They are different kinds of paint.
The same difference applies the other way round: Pixie Pink 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 Pixie Pink on the colour wheel See Medium Magenta on the colour wheel
All matches: Pixie Pink equivalents · Medium Magenta equivalents