This is Part Id of the Display Showdown: Nexus One vs. iPhone 3GS series taking a closer look at the Nexus One’s Display Power Consumption and Display Spectra.
Display Power Consumption
On an OLED display power is consumed only when it is emitting light. On a totally black screen the OLED display is consuming next to nothing; the driving circuitry does consume just a bit.
The blue OLEDs consume the most amount of power but produces the least amount of brightness resulting in a luminous efficiency of just 10%. As noted before, the Nexus One has a blue tint due to its high color temperature of 8870° Kelvin. By reducing power to the blue OLEDs the Nexus One will benefit from better color accuracy, enhance battery life and reduce differential aging of the blue OLEDs.
Display Spectra
The display spectra is the spectrum of the backlight filtered through the individual red, green, and blue sub-pixel filters within the panel. Because OLEDs are emissive the spectra of the Nexus One is the sum of the individual red, green, and blue OLED spectra, partially obstructed by the touch and anti-reflection layers. By using Konica Minolta’s CS-2000 Spectroradiometer, the OLED’s red, green, and blue spectra are narrow due to their high color saturation.
You can find more technical and in-depth explanations at DisplayMate.