ΔE 12.5, fair: the same colour family, but not a straight swap. Intermediate Blue (US Navy) is a little darker, more saturated, cooler than Runic Cobalt.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Intermediate Blue (US Navy) is a little darker, more saturated, cooler than Runic Cobalt.
The same difference applies the other way round: Runic Cobalt is a little 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 Runic Cobalt on the colour wheel See Intermediate Blue (US Navy) on the colour wheel
All matches: Runic Cobalt equivalents · Intermediate Blue (US Navy) equivalents