Well, I've had 2 TB irises change colors and I know that I didn't do it. (No money and no paintbrush.) One changed last year and instead of yellow, it's yellow and white. The other was a dark purple and now it's purple and white. These were planted in 2016 (I think.) Who knows.
If I have my terminology correct, the 'falls' have retained their original colors. It's the 'standards' that changed.
Apologies for hopping into someone else's question.
