Dark Sky vs Blue Black

How close are they?

ΔE 13.1, fair: the same colour family, but not a straight swap. Blue Black is a little darker, much more muted, cooler than Dark Sky.

Can I use Blue Black instead of Dark Sky?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Blue Black is a little darker, much more muted, cooler than Dark Sky.

Can I use Dark Sky instead of Blue Black?

The same difference applies the other way round: Dark Sky is a little lighter, much 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.