I find this a.m. that my cistus purpureus has thrown a white 'sport'!
Neat! Once in a while I'll find something with the wrong number of petals, but I don't think I've ever had a color change. Once in a very great while I'll find a color sport in the wild, but since it's in a park I can't take it.
How hot does it get where you are? Years ago, a friend of mine had an erigeron and it didn't live long. She thought that it was too hot here for it.