ΔE 9.6, close: similar, with a visible difference side by side. Burnt Umber is a little darker, warmer than Tree Ancient.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Burnt Umber is a little darker, warmer than Tree Ancient.
The same difference applies the other way round: Tree Ancient 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 Tree Ancient on the colour wheel See Burnt Umber on the colour wheel
All matches: Tree Ancient equivalents · Burnt Umber equivalents