ΔE 12.8, fair: the same colour family, but not a straight swap. Violet Vamp is noticeably darker than Translucent Purple.
Can I use Violet Vamp instead of Translucent Purple?
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Violet Vamp is noticeably darker than Translucent Purple.
Can I use Translucent Purple instead of Violet Vamp?
The same difference applies the other way round: Translucent Purple is noticeably lighter.
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.