ΔE 13.9, fair: the same colour family, but not a straight swap. Beasty Brown is noticeably darker, warmer than T'au Light Ochre.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Beasty Brown is noticeably darker, warmer than T'au Light Ochre.
The same difference applies the other way round: T'au Light Ochre is noticeably 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 T'au Light Ochre on the colour wheel See Beasty Brown on the colour wheel
All matches: T'au Light Ochre equivalents · Beasty Brown equivalents