T'au Light Ochre vs Yellow Ochre

How close are they?

ΔE 10.6, fair: the same colour family, but not a straight swap. Yellow Ochre is a little lighter, more saturated than T'au Light Ochre.

Can I use Yellow Ochre instead of T'au Light Ochre?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Yellow Ochre is a little lighter, more saturated than T'au Light Ochre.

Can I use T'au Light Ochre instead of Yellow Ochre?

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.