I do agree the same Iris can appear lighter or darker depending on weather, health, etc: But it stays within the same color range. There are also the broken color Irises and some can appear quite different from bloom to bloom.
But I have been growing Irises for 10 years and have lots, and have never had one change from a yellow to a purple, etc;
I have had people tell me they didn't want to invest any money in Irises because they will all just turn purple but that's so untrue, and well, just sad, cause they are missing so much!
