Vinay sent me a really interesting email which pointed to this site.
Blackle is the black version of Google. And since the amount to usage of Google is bound to increase it makes sense using blackle.Another fact is that it doesnt save much energy from LCD displays which are very popular today but does save a chunk from CRT displays
Blackle saves energy because the screen is predominantly black. “Image displayed is primarily a function of the user’s color settings and desktop graphics, as well as the color and size of open application windows; a given monitor requires more power to display a white (or light) screen than a black (or dark) screen.” Roberson et al, 2002
In January 2007 a blog post titled Black Google Would Save 750 Megawatt-hours a Year proposed the theory that a black version of the Google search engine would save a fair bit of energy due to the popularity of the search engine. Since then there has been skepticism about the significance of the energy savings that can be achieved and the cost in terms of readability of black web pages.
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.