ΔE 24.3, loose: different enough that you should pick on purpose. Muddy Wash is noticeably lighter, much more muted, cooler than Sepia Tone.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 24). Muddy Wash is noticeably lighter, much more muted, cooler than Sepia Tone.
The same difference applies the other way round: Sepia 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 Sepia Tone on the colour wheel See Muddy Wash on the colour wheel
All matches: Sepia Tone equivalents · Muddy Wash equivalents