Pink Flesh vs Reddish Flesh

How close are they?

ΔE 16.1, loose: different enough that you should pick on purpose. Reddish Flesh is much more saturated, warmer than Pink Flesh.

Can I use Reddish Flesh instead of Pink Flesh?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Reddish Flesh is much more saturated, warmer than Pink Flesh.

Can I use Pink Flesh instead of Reddish Flesh?

The same difference applies the other way round: Pink Flesh 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.