As I was tissue propagating more Shimai, a sport that will consistently appear when the bloom is not true is this cream colored flower with green edges. I have relegated those outcomes to the compost pile. For some reason I must have placed one of them to the side. I have no recollection as to why other then I believe the blooms on these were a bit larger then most of the blooms of the plants that on occasion would bloom this way. I noticed the blooms were very long lasting as other blooms tend to be when there is a significant amount of green present. As I watched the flowers develop I noticed a very definite color change with age. The photographs below are an attempt to illustrate this but the lighting was a challenge such that the balance of purple-cream-green reflects that of what you actually see in person. These are not the bestI can obtain at this time.
The above image is of a newly opening bloom typical of a common sport of Shimai
The above image is a bloom that is mature and demonstrating the purple coloration over the white/cream background with some diminishing of the green edges. Click on the image to enlarge and see the details.
So you can compare and contract between the newly open bloom and the mature bloom. The newly opened bloom is white star shaped bloom with strong green edges. As the bloom matures the green disparates somewhat and purple coloration begins to appear throughout the petal.