ΔE 14.5, fair: the same colour family, but not a straight swap. Hydra Turquoise is a little lighter, cooler than Cold Open.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Hydra Turquoise is a little lighter, cooler than Cold Open.
The same difference applies the other way round: Cold Open is a little darker, 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.
See Cold Open on the colour wheel See Hydra Turquoise on the colour wheel
All matches: Cold Open equivalents · Hydra Turquoise equivalents