Answer: I believe you! We've had enough questions about this over the years that we know it's not a fluke. The phenomenon seems to be the result of stress, especially when iris rhizomes are left exposed out of the ground for a while, as yours were. Iris growers verify this fact, but they don't yet understand the mechanism that causes the color change. I'm not sure if yours will ever revert to the yellow color you cherish, so it's best to play it safe and obtain some from your friends in Tulsa. I can imagine the yellow and purple will look great together.
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