ΔE 22.3, loose: different enough that you should pick on purpose. Arcane Purple is noticeably darker, more muted, warmer than Shyish Purple.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 22). Arcane Purple is noticeably darker, more muted, warmer than Shyish Purple.
The same difference applies the other way round: Shyish Purple is noticeably 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 Shyish Purple on the colour wheel See Arcane Purple on the colour wheel
All matches: Shyish Purple equivalents · Arcane Purple equivalents