ΔE 11.5, fair: the same colour family, but not a straight swap. Dark Purple is a little darker, more muted, warmer than Gothic Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Dark Purple is a little darker, more muted, warmer than Gothic Blue.
The same difference applies the other way round: Gothic Blue is a little lighter, more saturated, 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 Gothic Blue on the colour wheel See Dark Purple on the colour wheel
All matches: Gothic Blue equivalents · Dark Purple equivalents