ΔE 6.7, close: similar, with a visible difference side by side. Desert Yellow is more saturated than British Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Desert Yellow is more saturated than British Brown.
The same difference applies the other way round: British Brown is more muted.
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 British Brown on the colour wheel See Desert Yellow on the colour wheel
All matches: British Brown equivalents · Desert Yellow equivalents