Genestealer Purple vs Light Violet

How close are they?

ΔE 19.8, loose: different enough that you should pick on purpose. Light Violet is noticeably lighter, cooler than Genestealer Purple.

Can I use Light Violet instead of Genestealer Purple?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Light Violet is noticeably lighter, cooler than Genestealer Purple.

Can I use Genestealer Purple instead of Light Violet?

The same difference applies the other way round: Genestealer Purple is noticeably darker, 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.