ΔE 14.0, fair: the same colour family, but not a straight swap. Royal Purple is a little lighter, warmer than Dark Navy Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Royal Purple is a little lighter, warmer than Dark Navy Blue.
The same difference applies the other way round: Dark Navy Blue is a little darker, 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 Dark Navy Blue on the colour wheel See Royal Purple on the colour wheel
All matches: Dark Navy Blue equivalents · Royal Purple equivalents