ΔE 21.6, loose: different enough that you should pick on purpose. Crimson Magenta is a little lighter, more muted, warmer than Pixie Pink. They are different kinds of paint: Army Painter Pixie Pink is an opaque base/layer paint and Green Stuff World Crimson 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 22). Crimson Magenta is a little lighter, more muted, warmer than Pixie Pink. They are different kinds of paint.
The same difference applies the other way round: Pixie Pink is a little darker, 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 Pixie Pink on the colour wheel See Crimson Magenta on the colour wheel
All matches: Pixie Pink equivalents · Crimson Magenta equivalents