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