Sepia Tone vs Caspian Flesh Wash

How close are they?

ΔE 22.5, loose: different enough that you should pick on purpose. Caspian Flesh Wash is noticeably lighter, cooler than Sepia Tone.

Can I use Caspian Flesh Wash instead of Sepia Tone?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Caspian Flesh Wash is noticeably lighter, cooler than Sepia Tone.

Can I use Sepia Tone instead of Caspian Flesh Wash?

The same difference applies the other way round: Sepia Tone is noticeably darker, 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.