ΔE 14.9, fair: the same colour family, but not a straight swap. Cobalt Blue is more saturated, warmer than Crystal Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Cobalt Blue is more saturated, warmer than Crystal Blue.
The same difference applies the other way round: Crystal Blue is 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 Crystal Blue on the colour wheel See Cobalt Blue on the colour wheel
All matches: Crystal Blue equivalents · Cobalt Blue equivalents