ΔE 9.5, close: similar, with a visible difference side by side. Skyshard is a little lighter than WWI German Light Blue.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Skyshard is a little lighter than WWI German Light Blue.
The same difference applies the other way round: WWI German Light Blue is a little darker.
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 WWI German Light Blue on the colour wheel See Skyshard on the colour wheel
All matches: WWI German Light Blue equivalents · Skyshard equivalents