Why does the background under total changes from bright green to yellow and then to red?
The color under each total (actual net income, expected net income and running total) gives your the meaning for the number you see. Net income as $100 can mean “great” or “close to zero” depending on your income. So Simple Home Budget informs you by color how good (more green) or not good (more red) things are (more yellow means “close to zero”).