A well set-up TV set should be able to display a full range of black through gray to white and ... a series of five boxes ranging from dark gray to white with a pair of moving white bars on a white ...

But it turns out that there is a secret black-and-white always-on display mode that might suit your needs better. The dimmed lock screen still shows the time, the date, and your widgets ...

In fact in newer liquid-crystal display, or LCD, monitors white is actually slightly more energy efficient than black. The notion that black screens save electricity certainly makes sense when you ...