Phoenix Red vs Medium Flesh

How close are they?

ΔE 20.3, loose: different enough that you should pick on purpose. Medium Flesh is noticeably lighter, more muted than Phoenix Red.

Can I use Medium Flesh instead of Phoenix Red?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Medium Flesh is noticeably lighter, more muted than Phoenix Red.

Can I use Phoenix Red instead of Medium Flesh?

The same difference applies the other way round: Phoenix Red 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.