ΔE 14.6, fair: the same colour family, but not a straight swap. Violet Vamp is noticeably lighter, more saturated, cooler than Dioxazine Violet.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Violet Vamp is noticeably lighter, more saturated, cooler than Dioxazine Violet.
The same difference applies the other way round: Dioxazine Violet is noticeably darker, 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 Dioxazine Violet on the colour wheel See Violet Vamp on the colour wheel
All matches: Dioxazine Violet equivalents · Violet Vamp equivalents