ΔE 7.1, close: similar, with a visible difference side by side. US Sand is a little darker, cooler than Zimmerit.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). US Sand is a little darker, cooler than Zimmerit.
The same difference applies the other way round: Zimmerit is a little lighter, 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 Zimmerit on the colour wheel See US Sand on the colour wheel
All matches: Zimmerit equivalents · US Sand equivalents