I haven’t found out why, but the pond I visit most often to photograph white water-lilies has been drained. I looked around and didn’t see where a beaver dam was removed but I would guess somewhere that is the case. At any rate, the pond is starting to fill again and yesterday I was able to find a few of the lilies. In one spot I found three alike. I’ve not seen one like this before.
There are both white and pink flowering plants there so I am guessing this is a natural hybrid. I’ve shot quite a few of these over the years and all have had sepals the same color as the petals. In posting on a native wildflower group page on Facebook, with some members being employed by the Native Plant Trust, I haven’t seen anyone say they have seen this before.