ΔE 9.4, close: similar, with a visible difference side by side. Sand Grey is a little darker, more muted, warmer than Screaming Skull.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Sand Grey is a little darker, more muted, warmer than Screaming Skull.
The same difference applies the other way round: Screaming Skull is a little lighter, more saturated, cooler.
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 Screaming Skull on the colour wheel See Sand Grey on the colour wheel
All matches: Screaming Skull equivalents · Sand Grey equivalents