ΔE 24.8, loose: different enough that you should pick on purpose. Light Violet is noticeably darker, cooler than Weird Elixir.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 25). Light Violet is noticeably darker, cooler than Weird Elixir.
The same difference applies the other way round: Weird Elixir is noticeably lighter, 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 Weird Elixir on the colour wheel See Light Violet on the colour wheel
All matches: Weird Elixir equivalents · Light Violet equivalents