Abyss Blue vs Violet

How close are they?

ΔE 16.1, loose: different enough that you should pick on purpose. Violet is noticeably darker, more saturated, warmer than Abyss Blue.

Can I use Violet instead of Abyss Blue?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Violet is noticeably darker, more saturated, warmer than Abyss Blue.

Can I use Abyss Blue instead of Violet?

The same difference applies the other way round: Abyss Blue is noticeably lighter, more muted, 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.