T'au Light Ochre vs Light Tan

How close are they?

ΔE 15.0, fair: the same colour family, but not a straight swap. Light Tan is noticeably lighter, more muted than T'au Light Ochre.

Can I use Light Tan 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 15). Light Tan is noticeably lighter, more muted than T'au Light Ochre.

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

The same difference applies the other way round: T'au Light Ochre is noticeably darker, more saturated.

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.