ΔE 13.4, fair: the same colour family, but not a straight swap. Midnight Purple is noticeably darker, warmer than Chancellor Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Midnight Purple is noticeably darker, warmer than Chancellor Blue.
The same difference applies the other way round: Chancellor Blue is noticeably 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 Chancellor Blue on the colour wheel See Midnight Purple on the colour wheel
All matches: Chancellor Blue equivalents · Midnight Purple equivalents