ΔE 8.9, close: similar, with a visible difference side by side. Khaki Bone is more saturated, warmer than Screaming Skull.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Khaki Bone is more saturated, warmer than Screaming Skull.
The same difference applies the other way round: Screaming Skull is more muted, 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 Khaki Bone on the colour wheel
All matches: Screaming Skull equivalents · Khaki Bone equivalents