ΔE 6.1, close: similar, with a visible difference side by side. Faded P.R.U. Blue is a little lighter than Caspian Blue.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Faded P.R.U. Blue is a little lighter than Caspian Blue.
The same difference applies the other way round: Caspian 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 Caspian Blue on the colour wheel See Faded P.R.U. Blue on the colour wheel
All matches: Caspian Blue equivalents · Faded P.R.U. Blue equivalents