Cheers Voyager. It seems my Eclipse 2018 theme was made when the clock numbers were white, now they have changed to black the theme is outdated. New themes do change the clock numbers to suit the background so a change of theme also works rather than just reverting back to default.
No it isn't. A hard reset will switch off the phone and restart it retaining all info and themes. A factory reset will remove all data and the phone will be as it was out of the box
Switching off and on the phone is a soft reset.