ΔE 12.5, fair: the same colour family, but not a straight swap. Medium Blue is noticeably darker, warmer than Griffon Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Medium Blue is noticeably darker, warmer than Griffon Blue.
The same difference applies the other way round: Griffon Blue is noticeably lighter, 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 Griffon Blue on the colour wheel See Medium Blue on the colour wheel
All matches: Griffon Blue equivalents · Medium Blue equivalents