ΔE 10.4, fair: the same colour family, but not a straight swap. Brilliant Blue is a little lighter, cooler than Ensign Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Brilliant Blue is a little lighter, cooler than Ensign Blue.
The same difference applies the other way round: Ensign Blue is a little darker, 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 Ensign Blue on the colour wheel See Brilliant Blue on the colour wheel
All matches: Ensign Blue equivalents · Brilliant Blue equivalents