ΔE 13.7, fair: the same colour family, but not a straight swap. AMT-7 Greyish Blue is a little lighter, much more muted than Duck Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). AMT-7 Greyish Blue is a little lighter, much more muted than Duck Blue.
The same difference applies the other way round: Duck Blue is a little darker, much 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 Duck Blue on the colour wheel See AMT-7 Greyish Blue on the colour wheel
All matches: Duck Blue equivalents · AMT-7 Greyish Blue equivalents