ΔE 7.4, close: similar, with a visible difference side by side. Iraqi Sand is a little darker than Middle Stone.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Iraqi Sand is a little darker than Middle Stone.
The same difference applies the other way round: Middle Stone 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 Middle Stone on the colour wheel See Iraqi Sand on the colour wheel
All matches: Middle Stone equivalents · Iraqi Sand equivalents