For the more energy conscious, or those on smartphones, there is a widespread belief that having a white or black background yields favourable power consumption. This in theory made sense, by having each pixel in a dormant state (or in the case of LED screens, unlit) would reduce power draw. But is this really true? What colour would it have to be, and exactly how much power does it save?
At least that’s the believe behind sites like Blackle, a black backgrounded Google search which in theory and over a mass-scale is supposed to be of some benefit. Fortunately, TechLogg has already done the hard work, with the overall result being – negligible. On a variety of LCD screens they tested ranging from 19″ to 24″, only a 3.16% reduction in power consumption would be had by changing to an all-white screen from an all-black screen.
Why is this so? Well for LCD screens, the backlight is generally pure white. By applying a black background on the screen, you are forcing all pixels to be fully engaged, effectively attempting to block this light out, hence consuming more energy. Also consider that the average LCD these days only consumes 30-40W of power (according to my Kill-A-Watt equivalent), which is a pittance, compared to other appliances such as fridges and heaters.
An exception to this rule is AMOLED screens, which take zero power when displaying a black image, which also explains how they can achieve such brilliant contrast ratios. Anyway, in short, it doesn’t really matter what colour you choose, find something that is easy on the eyes and go with that. You will get FAR more energy efficiency by turning down the backlight brightness on your display than playing around with the colours.