Light Ghost Grey FS 36375 vs Ash Grey

How close are they?

ΔE 7.7, close: similar, with a visible difference side by side. Ash Grey is a little darker than Light Ghost Grey FS 36375.

Can I use Ash Grey instead of Light Ghost Grey FS 36375?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Ash Grey is a little darker than Light Ghost Grey FS 36375.

Can I use Light Ghost Grey FS 36375 instead of Ash Grey?

The same difference applies the other way round: Light Ghost Grey FS 36375 is a little lighter.

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.