ΔE 13.6, fair: the same colour family, but not a straight swap. Stormfang is noticeably lighter, more saturated, warmer than RAF PRU Blue BS381C/636.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Stormfang is noticeably lighter, more saturated, warmer than RAF PRU Blue BS381C/636.
The same difference applies the other way round: RAF PRU Blue BS381C/636 is noticeably darker, more muted, cooler.
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 RAF PRU Blue BS381C/636 on the colour wheel See Stormfang on the colour wheel
All matches: RAF PRU Blue BS381C/636 equivalents · Stormfang equivalents