ΔE 16.2, loose: different enough that you should pick on purpose. German Yellow is noticeably darker, more saturated, cooler than Naples Yellow Hue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). German Yellow is noticeably darker, more saturated, cooler than Naples Yellow Hue.
The same difference applies the other way round: Naples Yellow Hue is noticeably lighter, more muted, 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 Naples Yellow Hue on the colour wheel See German Yellow on the colour wheel
All matches: Naples Yellow Hue equivalents · German Yellow equivalents