Parity Diamonds

What is the Parity Diamonds rule?

Parity Diamonds is a variant sudoku rule: a black diamond means the two cells it touches have the same odd/even parity; a white diamond means they have different parity.

In every puzzle here the setter’s own rules text is shown beside the board, so the exact wording for the puzzle you are solving is always one glance away. All normal sudoku rules apply unless the setter says otherwise.