Frost Blue vs Deep Sky Blue

How close are they?

ΔE 14.5, fair: the same colour family, but not a straight swap. Deep Sky Blue is noticeably darker, warmer than Frost Blue.

Can I use Deep Sky Blue instead of Frost Blue?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Deep Sky Blue is noticeably darker, warmer than Frost Blue.

Can I use Frost Blue instead of Deep Sky Blue?

The same difference applies the other way round: Frost Blue is noticeably lighter, 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.