Turquoise (Phthalo) vs Ink Black Green

How close are they?

ΔE 12.3, fair: the same colour family, but not a straight swap. Ink Black Green is a little darker, more muted, warmer than Turquoise (Phthalo).

Can I use Ink Black Green instead of Turquoise (Phthalo)?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Ink Black Green is a little darker, more muted, warmer than Turquoise (Phthalo).

Can I use Turquoise (Phthalo) instead of Ink Black Green?

The same difference applies the other way round: Turquoise (Phthalo) 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.