RLM 76 Light Blue vs Russ. AF Light Blue

How close are they?

ΔE 7.5, close: similar, with a visible difference side by side. Russ. AF Light Blue is a little darker, more saturated than RLM 76 Light Blue.

Can I use Russ. AF Light Blue instead of RLM 76 Light Blue?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Russ. AF Light Blue is a little darker, more saturated than RLM 76 Light Blue.

Can I use RLM 76 Light Blue instead of Russ. AF Light Blue?

The same difference applies the other way round: RLM 76 Light Blue is a little lighter, 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.