RAF Azure Blue vs Deep Sky Blue

How close are they?

ΔE 10.4, fair: the same colour family, but not a straight swap. Deep Sky Blue is a little darker, more saturated, cooler than RAF Azure Blue.

Can I use Deep Sky Blue instead of RAF Azure Blue?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Deep Sky Blue is a little darker, more saturated, cooler than RAF Azure Blue.

Can I use RAF Azure Blue instead of Deep Sky Blue?

The same difference applies the other way round: RAF Azure Blue is a little lighter, more muted, 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.