ΔE 21.1, loose: different enough that you should pick on purpose. Flat Flesh is noticeably lighter, more muted than Transparent Brown Iron Oxide.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Flat Flesh is noticeably lighter, more muted than Transparent Brown Iron Oxide.
The same difference applies the other way round: Transparent Brown Iron Oxide 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 Transparent Brown Iron Oxide on the colour wheel See Flat Flesh on the colour wheel
All matches: Transparent Brown Iron Oxide equivalents · Flat Flesh equivalents