ΔE 10.8, fair: the same colour family, but not a straight swap. Black Rose Immortal is a little lighter, more saturated, warmer than Ashroot.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Black Rose Immortal is a little lighter, more saturated, warmer than Ashroot.
The same difference applies the other way round: Ashroot 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 Ashroot on the colour wheel See Black Rose Immortal on the colour wheel
All matches: Ashroot equivalents · Black Rose Immortal equivalents