ΔE 39.6, loose: different enough that you should pick on purpose. Ink Violet is noticeably lighter, much more saturated than Carbon Black INK.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 40). Ink Violet is noticeably lighter, much more saturated than Carbon Black INK.
The same difference applies the other way round: Carbon Black INK is noticeably darker, much more muted.
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 Carbon Black INK on the colour wheel See Ink Violet on the colour wheel
All matches: Carbon Black INK equivalents · Ink Violet equivalents