ΔE 20.2, loose: different enough that you should pick on purpose. Sandy Yellow is noticeably lighter, cooler than T'au Light Ochre.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Sandy Yellow is noticeably lighter, cooler than T'au Light Ochre.
The same difference applies the other way round: T'au Light Ochre is noticeably darker, 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 T'au Light Ochre on the colour wheel See Sandy Yellow on the colour wheel
All matches: T'au Light Ochre equivalents · Sandy Yellow equivalents