This is exceptional because of how a single change can make such a potentially large impact.
When your screen is white - an empty word page, or the Google page, your computer consumes 74 watts, and when it’s black it consumes only 59 watts.
Mark Ontkush wrote an article about the energy saving that would be achieved if Google had a black screen, taking in account the huge number of page views. According to his calculations, 750 mWh per year would be saved. That’s the kWh per year that 1,000 average US refrigerators would use. Ok, so it’s not an enormous amount to stave off global warming, but it’s significant just by doing something small like changing the color. (Of course in the world of graphic or visual design, changing a color isn’t small.)
In a response to this article Google created a black version of its search engine, called BLACKLE, with the exact same functions as the white version but with a lower energy consumption. Check it out !
P.S. Bank of America is a key sponsor of the NYC campaign from City Hall, GreeNYC http://www.nyc.gov/html/planyc2030/html/greenyc/greenyc.shtml, which promotes suggestions to fulfill its tagline: “Small Steps, Big Strides”. GE and ConEd are the other two corporate sponsors.