Sapphire Blue vs Russ. AF Grey N.8

How close are they?

ΔE 13.7, fair: the same colour family, but not a straight swap. Russ. AF Grey N.8 is a little darker, more muted, cooler than Sapphire Blue.

Can I use Russ. AF Grey N.8 instead of Sapphire Blue?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Russ. AF Grey N.8 is a little darker, more muted, cooler than Sapphire Blue.

Can I use Sapphire Blue instead of Russ. AF Grey N.8?

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