ΔE 17.1, loose: different enough that you should pick on purpose. Gothic Blue is more muted, cooler than Purple.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Gothic Blue is more muted, cooler than Purple.
The same difference applies the other way round: Purple is more saturated, warmer.
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 Purple on the colour wheel See Gothic Blue on the colour wheel
All matches: Purple equivalents · Gothic Blue equivalents