Final answer:
Without any clicks, the 'topButton' will be blue as the last setProperty called before the event handler changes it to blue.
Step-by-step explanation:
If the user does NOT click the "topButton", the color of "topButton" when the program finishes running will be blue. This is because the setProperty functions are called sequentially, changing the background color from "red" to "blue".
Since the button is not clicked, the event handler that would change the color to "green" and then to "orange" is not triggered.