ΔE 11.7, fair: the same colour family, but not a straight swap. Dark Green Blue is a little lighter, more saturated, warmer than Tyrian Navy.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Dark Green Blue is a little lighter, more saturated, warmer than Tyrian Navy.
The same difference applies the other way round: Tyrian Navy is a little darker, 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 Tyrian Navy on the colour wheel See Dark Green Blue on the colour wheel
All matches: Tyrian Navy equivalents · Dark Green Blue equivalents