ΔE 6.6, close: similar, with a visible difference side by side. IDF Sand Grey is a little lighter, more muted than Dust.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). IDF Sand Grey is a little lighter, more muted than Dust.
The same difference applies the other way round: Dust is a little darker, 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.
See Dust on the colour wheel See IDF Sand Grey on the colour wheel
All matches: Dust equivalents · IDF Sand Grey equivalents