ΔE 9.4, close: similar, with a visible difference side by side. Permanent Violet Dark is more muted, warmer than Royal Purple. They are different kinds of paint: Army Painter Royal Purple is a metallic and Golden Permanent Violet Dark is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Permanent Violet Dark is more muted, warmer than Royal Purple. They are different kinds of paint.
The same difference applies the other way round: Royal Purple is 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 Royal Purple on the colour wheel See Permanent Violet Dark on the colour wheel
All matches: Royal Purple equivalents · Permanent Violet Dark equivalents