Have you noticed that some bi-colored petunias change with temperature, sunlight exposure, and age of blossom? Here's a look at Petunia Glow™ Blue Stardust.
Name: Leon Indiana (Zone 5a) Light is the shadow of God!
I was beginning to think I had done something with fertilizer or watering to cause this. We had Hula Hoop Blue & Fortunia Purple Picotee in containers. The hot weather in August apparently zapped the dark colors from them leaving mostly white. Purple Picotee in the left picture died altogether. Thanks Joanne for posting this. I learned something today.