Bright Sapphire vs Artic Blue

How close are they?

ΔE 18.2, loose: different enough that you should pick on purpose. Artic Blue is a little darker, much more muted than Bright Sapphire.

Can I use Artic Blue instead of Bright Sapphire?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Artic Blue is a little darker, much more muted than Bright Sapphire.

Can I use Bright Sapphire instead of Artic Blue?

The same difference applies the other way round: Bright Sapphire is a little lighter, 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.