Hydra Turquoise vs Freezing Moon

How close are they?

ΔE 15.7, loose: different enough that you should pick on purpose. Freezing Moon is a little lighter, much more muted than Hydra Turquoise.

Can I use Freezing Moon instead of Hydra Turquoise?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Freezing Moon is a little lighter, much more muted than Hydra Turquoise.

Can I use Hydra Turquoise instead of Freezing Moon?

The same difference applies the other way round: Hydra Turquoise is a little darker, much more saturated.

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.