ΔE 21.5, loose: different enough that you should pick on purpose. Crimson Magenta is a little darker, much more saturated, warmer than Talisman Purple. They are different kinds of paint: Army Painter Talisman Purple 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 21). Crimson Magenta is a little darker, much more saturated, warmer than Talisman Purple. They are different kinds of paint.
The same difference applies the other way round: Talisman Purple is a little lighter, much more muted, 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 Talisman Purple on the colour wheel See Crimson Magenta on the colour wheel
All matches: Talisman Purple equivalents · Crimson Magenta equivalents