LEDs are extremely efficient, and when it comes to single colors such as red or green commonly used in traffic lights or toys, they can’t be beat. But those aren’t the colors we want to light up our homes and offices. Our eyes prefer the warm, white light produced by the sun, and when it’s not available, we’ll take the similar glow produced by CFLs and incandescent bulbs. Soon, however, those traditional options won’t be available, and good riddance. They suck up way more energy than should be necessary to light a room. Scientists have been worki...