Phal- newer flowers differnt color

[murphy48]

I've had this phal for a few weeks and yesterday one of the buds opened. The flower is much darker than the rest of the flowers. Some of the old flowers look very washed out in comparison. It's even more dramatic than what the pictures show. What would cause the color difference? I really like the intensity of the new flower so I'd love to know what might cause this so I can get the darker flowers when it blooms again in the future.

Thanks, Kristen