ΔE 8.4, close: similar, with a visible difference side by side. Dark Highlights is a little darker, more muted, cooler than Leather Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Dark Highlights is a little darker, more muted, cooler than Leather Brown.
The same difference applies the other way round: Leather Brown is a little lighter, more saturated, 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 Leather Brown on the colour wheel See Dark Highlights on the colour wheel
All matches: Leather Brown equivalents · Dark Highlights equivalents