Hi Catherine,

Your flower looks very healthy, it does not display symptoms of disease. I see that it is a hybrid. It may be that it's normal for older leaves to turn darker. I can't really say much to this, let's see how it does. Some times plants revert to different colors or even a lack of pigment.

If it stays healthy there is no problem. Let me know if it looks like it's declining.

Sally Granath

St. Louis County MG