ΔE 6.3, close: similar, with a visible difference side by side. Our swatches for the two are almost the same.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). The swatches are almost the same.
The same difference applies the other way round.
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 WWI British Khaki Brown Base on the colour wheel See Tree Ancient on the colour wheel
All matches: WWI British Khaki Brown Base equivalents · Tree Ancient equivalents