ΔE 6.1, close: similar, with a visible difference side by side. Transparent Brown is a little darker, warmer than Leather Brown. They are different kinds of paint: Army Painter Leather Brown is an opaque base/layer paint and Pro Acryl Transparent Brown is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Transparent Brown is a little darker, warmer than Leather Brown. They are different kinds of paint.
The same difference applies the other way round: Leather Brown is a little lighter, cooler.
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 Transparent Brown on the colour wheel
All matches: Leather Brown equivalents · Transparent Brown equivalents