ΔE 6.4, close: similar, with a visible difference side by side. Pale Blue Grey is a little darker, more saturated than Moonstone Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Pale Blue Grey is a little darker, more saturated than Moonstone Grey.
The same difference applies the other way round: Moonstone 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.
See Moonstone Grey on the colour wheel See Pale Blue Grey on the colour wheel
All matches: Moonstone Grey equivalents · Pale Blue Grey equivalents