ΔE 17.1, loose: different enough that you should pick on purpose. Blue Violet is a little darker, more muted, warmer than Thunder Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Blue Violet is a little darker, more muted, warmer than Thunder Blue.
The same difference applies the other way round: Thunder Blue is a little lighter, 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 Thunder Blue on the colour wheel See Blue Violet on the colour wheel
All matches: Thunder Blue equivalents · Blue Violet equivalents