ΔE 9.0, close: similar, with a visible difference side by side. Yellow Ochre is a little lighter, more saturated than T'au Light Ochre. They are different kinds of paint: Citadel T'au Light Ochre is an opaque base/layer paint and Golden Yellow Ochre 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 9). Yellow Ochre is a little lighter, more saturated than T'au Light Ochre. They are different kinds of paint.
The same difference applies the other way round: T'au Light Ochre is a little darker, more muted.
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 T'au Light Ochre on the colour wheel See Yellow Ochre on the colour wheel
All matches: T'au Light Ochre equivalents · Yellow Ochre equivalents