Turbo vs Amethyst Purple

How close are they?

ΔE 18.0, loose: different enough that you should pick on purpose. Amethyst Purple is more muted, cooler than Turbo.

Can I use Amethyst Purple instead of Turbo?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Amethyst Purple is more muted, cooler than Turbo.

Can I use Turbo instead of Amethyst Purple?

The same difference applies the other way round: Turbo is 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.