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