ΔE 11.3, fair: the same colour family, but not a straight swap. French Blue is more saturated, warmer than Mirage Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). French Blue is more saturated, warmer than Mirage Blue.
The same difference applies the other way round: Mirage Blue is more muted, cooler.
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 Mirage Blue on the colour wheel See French Blue on the colour wheel
All matches: Mirage Blue equivalents · French Blue equivalents