Intermediate Blue (US Navy) vs Russian AF Grey N.7

How close are they?

ΔE 7.6, close: similar, with a visible difference side by side. Russian AF Grey N.7 is more muted than Intermediate Blue (US Navy).

Can I use Russian AF Grey N.7 instead of Intermediate Blue (US Navy)?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Russian AF Grey N.7 is more muted than Intermediate Blue (US Navy).

Can I use Intermediate Blue (US Navy) instead of Russian AF Grey N.7?

The same difference applies the other way round: Intermediate Blue (US Navy) is 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.