ΔE 6.2, close: similar, with a visible difference side by side. White Grey is a little darker, cooler than J.A. Gray.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). White Grey is a little darker, cooler than J.A. Gray.
The same difference applies the other way round: J.A. Gray is a little lighter, warmer.
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 J.A. Gray on the colour wheel See White Grey on the colour wheel
All matches: J.A. Gray equivalents · White Grey equivalents