ΔE 32.7, loose: different enough that you should pick on purpose. Martian Orange is noticeably darker, much more saturated than Seraphim Flesh.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 33). Martian Orange is noticeably darker, much more saturated than Seraphim Flesh.
The same difference applies the other way round: Seraphim Flesh is noticeably lighter, much more muted.
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 Seraphim Flesh on the colour wheel See Martian Orange on the colour wheel
All matches: Seraphim Flesh equivalents · Martian Orange equivalents