ΔE 14.6, fair: the same colour family, but not a straight swap. Inktense Violet is much more saturated than Diabolic Plum. They are different kinds of paint: Army Painter Diabolic Plum is an opaque base/layer paint and Scale75 Inktense Violet 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 15). Inktense Violet is much more saturated than Diabolic Plum. They are different kinds of paint.
The same difference applies the other way round: Diabolic Plum is much 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 Diabolic Plum on the colour wheel See Inktense Violet on the colour wheel
All matches: Diabolic Plum equivalents · Inktense Violet equivalents