Conditional highlighting of booleans in Apple Numbers

It looks like Apple has implemented this functionality natively now (at least on Numbers 11.2) so that no language-dependent workaround is needed.

When setting up a Highlighting Rule, choose Cell as type, and there you will find the "Is true""Is false" rules

A boolean in Numbers seems to be represented internally as a String already. Setting "text is TRUE" and "text is FALSE" worked for me.

The OP does not specify how TRUE or FALSE are represented in the cell, but as was stated in another answer, using text is rule will work. This also works for checkboxes, they resolve to TRUE and FALSE as well.

• Text is TRUE add formatting
• Text is FALSE add other formatting

This works for the result of a formula returning the text TRUE or FALSE. If one is using numbers for Booleans, i.e.: 0 or not 0 then use a number rule.

• Number is equal to 0 [zero representing FALSE] add formatting
• Number is not equal to 0 [in the case of any number is TRUE] other formatting

See screenshots for examples.