Bright Sapphire vs Light Phthalo Blue

How close are they?

ΔE 11.0, fair: the same colour family, but not a straight swap. Light Phthalo Blue is a little lighter, warmer than Bright Sapphire.

Can I use Light Phthalo Blue instead of Bright Sapphire?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Light Phthalo Blue is a little lighter, warmer than Bright Sapphire.

Can I use Bright Sapphire instead of Light Phthalo Blue?

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