ΔE 13.9, fair: the same colour family, but not a straight swap. Carbon Black is noticeably darker, more muted than Dark Drab.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Carbon Black is noticeably darker, more muted than Dark Drab.
The same difference applies the other way round: Dark Drab is noticeably lighter, more saturated.
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 Dark Drab on the colour wheel See Carbon Black on the colour wheel
All matches: Dark Drab equivalents · Carbon Black equivalents