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