Within a color cluster, there can only be 2 parities. Each candidate within the cluster is assigned to one of these parities. The 2 parities are each other's opposite.
For each pair of candidates within the cluster, there are two possible situations:
- Parities are the same
- These candidates are equivalent. They must be true or false together.
- Parities are opposite
- Only one of these candidates will be true. The other must be false.