My brother in law inherited the family Christmas cactus which always had red flowers. He gave me some "leaves" and my little C cactus is healthy and growing well. It is now flowering with lovely white flowers with pink stamens. ??? Any ideas what happened? Nora A.
What most likely happened is that you got a "sport", or a genetic mutant that arose on one part of the larger plant. The cutting you planted must have carried the mutation. Here is more about plant sports:
Some Christmas cactus plants do produce white blooms, so now it seems you have one of those: https://extension.psu.edu/plants/master-gardener/counties/adams/news/2012/getting-christmas-cactus-to-bloom