ΔE 10.2, fair: the same colour family, but not a straight swap. Obsidian Black is a little darker than Black Ice.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Obsidian Black is a little darker than Black Ice.
The same difference applies the other way round: Black Ice is a little lighter.
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 Black Ice on the colour wheel See Obsidian Black on the colour wheel
All matches: Black Ice equivalents · Obsidian Black equivalents