Rainy Grey vs Nocturna Shadow

How close are they?

ΔE 7.3, close: similar, with a visible difference side by side. Nocturna Shadow is a little darker, more saturated than Rainy Grey.

Can I use Nocturna Shadow instead of Rainy Grey?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Nocturna Shadow is a little darker, more saturated than Rainy Grey.

Can I use Rainy Grey instead of Nocturna Shadow?

The same difference applies the other way round: Rainy Grey 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.