ΔE 7.8, close: similar, with a visible difference side by side. IDF Blue is more saturated, cooler than Faded Gray (Blassgrau).
Usually, if you are not matching paint already on the model. Close match (ΔE 8). IDF Blue is more saturated, cooler than Faded Gray (Blassgrau).
The same difference applies the other way round: Faded Gray (Blassgrau) is 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 Faded Gray (Blassgrau) on the colour wheel See IDF Blue on the colour wheel
All matches: Faded Gray (Blassgrau) equivalents · IDF Blue equivalents