It's the other way around, unless it's still the 90s.

Can't go any deeper, so here goes:

LCDs are clear by default with a big light behind them. You can see this on any Apple laptop, the glowing logo is just the backlight (watch it fade as you lower brightness or try shining a flashlight through it). White (clear) is the default state, so it takes power to make a color. Think of an LCD watch, all of the text is black because LCDs can't create light (those are LEDs).

http://www.scientificamerican.com/article.cfm?id=fact-or-fic...

Of course, it's a minuscule difference, since I'm guessing that the giant light probably uses most of the power, not the actual LCD.

This is the opposite of CRTs (hence the "90s" comment), which do actually create brightness per-pixel.