N8 Neutral Gray vs Russ. AF Light Blue

How close are they?

ΔE 18.1, loose: different enough that you should pick on purpose. Russ. AF Light Blue is a little darker, much more saturated than N8 Neutral Gray.

Can I use Russ. AF Light Blue instead of N8 Neutral Gray?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Russ. AF Light Blue is a little darker, much more saturated than N8 Neutral Gray.

Can I use N8 Neutral Gray instead of Russ. AF Light Blue?

The same difference applies the other way round: N8 Neutral Gray is a little lighter, much more muted.

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.