ΔE 9.3, close: similar, with a visible difference side by side. Barley Gray BS4800/18B21 is a little darker than Shark White.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Barley Gray BS4800/18B21 is a little darker than Shark White.
The same difference applies the other way round: Shark White 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 Shark White on the colour wheel See Barley Gray BS4800/18B21 on the colour wheel
All matches: Shark White equivalents · Barley Gray BS4800/18B21 equivalents