I really did (sort of).
For years I worked at the Minnesota State Horticultural Society, publisher of Northern Gardener magazine. One day we got a call that got forwarded to me. It was from a Minnesota-based screenwriter who was working on writing an episode of the then wildly popular Murder, She Wrote.
He was looking for a plant that had the potential to be one color one season and another color the next. It was integral to the plot somehow. Immediately, a Hydrangea ‘Nikko Blue’ came to mind (‘Endless Summer’ was still years from market).
I told him that in a more acid soil the flowers are a vivid blue; in more alkaline soil they are pink. All a gardener would need to do is add aluminum sulfate to the soil to make flowers bluer or add lime to soil to make flowers pinker. This amendment would be added to the plant root zone in late autumn or early spring. The show takes place in the more temperate regions of eastern U.S., so the Zone 6 temperament was not an issue.
He asked me if I was sure. I told him absolutely. He thanked me and told me that he was naming the gardener in the episode Eric. Keep an eye on Murder, She Wrote reruns for me.