As per DOE Energy Star Desktop Information ”White and bright colors (especially in backgrounds) can use up to 20% more power than black or dark colors.“
Blackle supports that concept and came up with search engine with back background to save energy. It basically uses google custom search with black background color. “Blackle saves energy because the screen is predominantly black… We believe that there is value in the concept because even if the energy savings are small, they all add up. Secondly we feel that seeing Blackle every time we load our web browser reminds us that we need to keep taking small steps to save energy.” says Blackle.
However Google says opposite to this. About saving the energy, Google says that
“One idea, suggested by the site called "Blackle" (which is not related to Google, by the way, though the site does use our custom search engine), is to reduce energy used by monitors by providing search with a black background. We applaud the spirit of the idea, but our own analysis as well as that of others shows that making the Google homepage black will not reduce energy consumption. To the contrary, on flat-panel monitors (already estimated to be 75% of the market), displaying black may actually increase energy usage. Detailed results from a new study confirm this.”
This seems to be contradictory statement with Google’s own decision to turn it’s back ground color to black on earth hour.
Irrespective of whether black background will save some energy or not, to support the effort to save energy SmashingFeeds.com, a simple online news aggregator, changed it’s back ground color to black. More details about this new design can be found on the blog.