So I have a pretty dark blog. I wonder if it hurts people's eyes when they read my blog. That is generally why people write on light backgrounds with dark writing... To ease eye strain.
But why a dark blog? I'm trying to save energy. Not too long ago, a few people calculated what the energy savings would be if Google changed their homepage from a white background to a black background. The energy savings would be something like 8.3 Megawatts of power per day.
The more we become conscious about our energy use, the more we realize that we use a whole lot of energy when we're not even trying to.