ΔE 34.4, loose: different enough that you should pick on purpose. Seraphim Sepia is noticeably lighter, much more muted, cooler than Orange Tone.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 34). Seraphim Sepia is noticeably lighter, much more muted, cooler than Orange Tone.
The same difference applies the other way round: Orange Tone is noticeably darker, much more saturated, warmer.
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 Orange Tone on the colour wheel See Seraphim Sepia on the colour wheel
All matches: Orange Tone equivalents · Seraphim Sepia equivalents