Your problem could have been rectified by simply turning the iFly off, then back on. The screen returns to the day time mode instead of returning to the last used state (which is a problem if you're flying at night, have a power interruption and the iFly re-boots.).
Or, you could have pushed the "Mode" button on the remote and the appropriate menu would have appeared, where you could have selected the day mode once again.
Then again, I have the 700, and perhaps the menu structure is different. I have to push the "Mode" button, then the "Day/Night Mode" option is in a separate column from the rest of the choices. When I select the "Day/Night Mode" it changes to another menu list, where I have to then choose between "Day", "Night", or "Close".