Darkoath Flesh vs Warm Brown

How close are they?

ΔE 30.5, loose: different enough that you should pick on purpose. Warm Brown is noticeably darker, much more muted than Darkoath Flesh.

Can I use Warm Brown instead of Darkoath Flesh?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 30). Warm Brown is noticeably darker, much more muted than Darkoath Flesh.

Can I use Darkoath Flesh instead of Warm Brown?

The same difference applies the other way round: Darkoath Flesh is noticeably lighter, much 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.