ΔE 63.5, loose: different enough that you should pick on purpose. Ink Red is much more saturated, warmer than Piggy Purple Ink.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 63). Ink Red is much more saturated, warmer than Piggy Purple Ink.
The same difference applies the other way round: Piggy Purple Ink is 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 Piggy Purple Ink on the colour wheel See Ink Red on the colour wheel
All matches: Piggy Purple Ink equivalents · Ink Red equivalents