Welcome to TFP!!!
I would ignore the red/green. [to answer your question directly, you can move the knob. It is intended, after you backwash/clean the filter to turn the knob until the green lines up with the actual pressure. Then the read is Hayward's recommended pressure to clean. In this case that would put you north of 30psi when you clean]
We don't recommend that. We recommend that you note your clean pressure, and when pressure rises 25%, the clean backwash again. In this case, assuming your clean pressure is 20, the you should clean when pressure rises to 24.
