ΔE 10.6, fair: the same colour family, but not a straight swap. T'au Light Ochre is a little darker than British Sand Yellow.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). T'au Light Ochre is a little darker than British Sand Yellow.
The same difference applies the other way round: British Sand Yellow is a little lighter.
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 British Sand Yellow on the colour wheel See T'au Light Ochre on the colour wheel
All matches: British Sand Yellow equivalents · T'au Light Ochre equivalents