ΔE 9.0, close: similar, with a visible difference side by side. Imperial Purple is more saturated than Warlock Magenta.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Imperial Purple is more saturated than Warlock Magenta.
The same difference applies the other way round: Warlock Magenta is more muted.
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 Warlock Magenta on the colour wheel See Imperial Purple on the colour wheel
All matches: Warlock Magenta equivalents · Imperial Purple equivalents