ΔE 11.9, fair: the same colour family, but not a straight swap. Amarth Blue is a little lighter, more muted, cooler than Crystal Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Amarth Blue is a little lighter, more muted, cooler than Crystal Blue.
The same difference applies the other way round: Crystal Blue is a little darker, more saturated, 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 Crystal Blue on the colour wheel See Amarth Blue on the colour wheel
All matches: Crystal Blue equivalents · Amarth Blue equivalents