ΔE 6.1, close: similar, with a visible difference side by side. Dark Sand is a little darker than Desert Sand.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Dark Sand is a little darker than Desert Sand.
The same difference applies the other way round: Desert Sand is a little lighter.
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 Desert Sand on the colour wheel See Dark Sand on the colour wheel
All matches: Desert Sand equivalents · Dark Sand equivalents