ΔE 7.1, close: similar, with a visible difference side by side. Light Brown is a little lighter, more muted than Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Light Brown is a little lighter, more muted than Brown.
The same difference applies the other way round: Brown is a little darker, more saturated.
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 Brown on the colour wheel See Light Brown on the colour wheel
All matches: Brown equivalents · Light Brown equivalents