ΔE 8.2, close: similar, with a visible difference side by side. Bone White is a little lighter, more saturated, cooler than Sand FS 33531.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Bone White is a little lighter, more saturated, cooler than Sand FS 33531.
The same difference applies the other way round: Sand FS 33531 is a little darker, more muted, 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 Sand FS 33531 on the colour wheel See Bone White on the colour wheel
All matches: Sand FS 33531 equivalents · Bone White equivalents