ΔE 47.0, loose: different enough that you should pick on purpose. Ink Yellow is noticeably lighter, much more saturated, warmer than Inktense Chestnut.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 47). Ink Yellow is noticeably lighter, much more saturated, warmer than Inktense Chestnut.
The same difference applies the other way round: Inktense Chestnut is noticeably darker, much 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 Inktense Chestnut on the colour wheel See Ink Yellow on the colour wheel
All matches: Inktense Chestnut equivalents · Ink Yellow equivalents