The biggest issue with those three hypotheses is one of them, the noticing the button, almost certainly isn't being tested. But, how the test goes will inform how people think about that hypothesis.
That doesn't test noticing the button, that tests clicking the button. If the color changes it is possible that fewer people notice it but are more likely to click in a way that increases total traffic. Or more people notice it but are less likely to click in a way that reduces traffic.
This is what I was driving at in my original comment - the intermediary steps are not of interest (from the POV of the hypothesis/overall experiment), so why mention them at all.