Turquoise vs Ink Black Green

How close are they?

ΔE 17.0, loose: different enough that you should pick on purpose. Ink Black Green is a little darker, more muted, warmer than Turquoise.

Can I use Ink Black Green instead of Turquoise?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Ink Black Green is a little darker, more muted, warmer than Turquoise.

Can I use Turquoise instead of Ink Black Green?

The same difference applies the other way round: Turquoise is a little 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.