Googling for "Oops"
Google “turned the lights out” for earth hour.
But if you have an LCD screen, a black pixel draws more current than a white one, because you have to energize the pixel. The low-energy state is “clear,” which lets the backlight through, and gives you white. So this thinking is very CRT, very yesterday. Not Google-y at all.
Yes, but as the information page states…
“As to why we don’t do this permanently – it saves no energy; modern displays use the same amount of power regardless of what they display.”
As you say, the white “lets the backlight through”, and it’s the backlight (a high frequency flourescent lamp) that consumes energy. Digital LCD watches can be powered for ten years on a tiny watch battery. The energy used to power the liquid crystal cells is negligible, probably less than the amount of energy needed to keep the little green light on the front of the monitor running.