The first prompt is fine, it's the following ones that are poor.

> Why is half the site blue now? I asked you to change one button.

> Half the site is blue. I asked for ONE button

Neither of these is an instruction to fix the problem, they're treating the AI like a person and telling it what it did wrong, expecting the implied admonishment to be enough to steer it back. But without an actual instruction, it just goes and does whatever it thinks will help, which is often arbitrary.

The response I would have used in this situation is

"The Cancel button is also blue now. Make sure the color change is only scoped to the Add to Cart button"

Most of the available responses throughout this "skit" are similar cases of expressing frustration first and guiding the result second.

Skip the emotion and say exactly what you want, and nothing besides that.