Pink Flesh vs Squid Pink

How close are they?

ΔE 29.1, loose: different enough that you should pick on purpose. Squid Pink is noticeably lighter, more saturated, cooler than Pink Flesh.

Can I use Squid Pink instead of Pink Flesh?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 29). Squid Pink is noticeably lighter, more saturated, cooler than Pink Flesh.

Can I use Pink Flesh instead of Squid Pink?

The same difference applies the other way round: Pink Flesh is noticeably darker, more muted, warmer.

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.