ΔE 13.2, fair: the same colour family, but not a straight swap. Dark Blue is a little darker, warmer than Brilliant Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Dark Blue is a little darker, warmer than Brilliant Blue.
The same difference applies the other way round: Brilliant Blue is a little lighter, 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 Brilliant Blue on the colour wheel See Dark Blue on the colour wheel
All matches: Brilliant Blue equivalents · Dark Blue equivalents