ΔE 9.2, close: similar, with a visible difference side by side. Intermediate Blue (US Navy) is a little lighter, more muted than Phalanx Blue.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Intermediate Blue (US Navy) is a little lighter, more muted than Phalanx Blue.
The same difference applies the other way round: Phalanx Blue is a little darker, more saturated.
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 Phalanx Blue on the colour wheel See Intermediate Blue (US Navy) on the colour wheel
All matches: Phalanx Blue equivalents · Intermediate Blue (US Navy) equivalents