ΔE 7.8, close: similar, with a visible difference side by side. Magenta is a little darker than Purple Alchemy. They are different kinds of paint: Army Painter Purple Alchemy is a one-coat contrast-style paint and Vallejo Magenta is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
✓ Herrick Games paint comparison chart lists these two as equivalents.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Magenta is a little darker than Purple Alchemy. They are different kinds of paint.
The same difference applies the other way round: Purple Alchemy is a little 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 Purple Alchemy on the colour wheel See Magenta on the colour wheel
All matches: Purple Alchemy equivalents · Magenta equivalents