When I worked with Rod McLellan Company in SF years ago there was a complex cross, Blc. My-My, that would bloom radically different colors on the same plant. It happened with a number of the plants of the cross. One would bloom dark purple in Jan-Feb, yellow w/cl in May-June, and white/cl in Sept-Oct. The size and form were the same (excellent). I have never encountered such a thing before or since. As a geneticist it has always puzzled me.