ΔE 9.6, close: similar, with a visible difference side by side. Sand Brown is more saturated, warmer than Dark Earth.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Sand Brown is more saturated, warmer than Dark Earth.
The same difference applies the other way round: Dark Earth is more muted, cooler.
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 Dark Earth on the colour wheel See Sand Brown on the colour wheel
All matches: Dark Earth equivalents · Sand Brown equivalents