Spectral Purple vs Light Violet

How close are they?

ΔE 19.4, loose: different enough that you should pick on purpose. Light Violet is noticeably lighter, more muted, cooler than Spectral Purple.

Can I use Light Violet instead of Spectral Purple?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Light Violet is noticeably lighter, more muted, cooler than Spectral Purple.

Can I use Spectral Purple instead of Light Violet?

The same difference applies the other way round: Spectral Purple is noticeably darker, more saturated, 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.