ΔE 12.6, fair: the same colour family, but not a straight swap. Anthraquinone Blue is a little darker, more saturated, cooler than Purple Tone. They are different kinds of paint: Army Painter Purple Tone is a wash/shade and Golden Anthraquinone Blue 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 13). Anthraquinone Blue is a little darker, more saturated, cooler than Purple Tone. They are different kinds of paint.
The same difference applies the other way round: Purple Tone is a little lighter, more muted, warmer.
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 Tone on the colour wheel See Anthraquinone Blue on the colour wheel
All matches: Purple Tone equivalents · Anthraquinone Blue equivalents