ΔE 17.9, loose: different enough that you should pick on purpose. Squid Pink is noticeably lighter, more muted than Light Plum.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Squid Pink is noticeably lighter, more muted than Light Plum.
The same difference applies the other way round: Light Plum is noticeably darker, 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 Light Plum on the colour wheel See Squid Pink on the colour wheel
All matches: Light Plum equivalents · Squid Pink equivalents