ΔE 18.0, loose: different enough that you should pick on purpose. Flat Flesh is more muted, warmer than Yellow Oxide.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Flat Flesh is more muted, warmer than Yellow Oxide.
The same difference applies the other way round: Yellow Oxide is more saturated, 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 Yellow Oxide on the colour wheel See Flat Flesh on the colour wheel
All matches: Yellow Oxide equivalents · Flat Flesh equivalents