ΔE 8.4, close: similar, with a visible difference side by side. US Sand is a little darker, cooler than Khaki Shadow.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). US Sand is a little darker, cooler than Khaki Shadow.
The same difference applies the other way round: Khaki Shadow 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 Khaki Shadow on the colour wheel See US Sand on the colour wheel
All matches: Khaki Shadow equivalents · US Sand equivalents