LCD televisions produce a black and colored image by selectively filtering a white light. The light was provided by a series of cold cathode fluorescent lamps (CCFLs) at the back of the screen. Today, most LCD-TV displays use white or colored LEDs as backlighting instead. Millions of individual LCD shutters, arranged in a grid, open and close to allow a metered amount of the white light through. Each shutter is paired with a colored filter to remove all but the red, green or blue (RGB) portion of the light from the original white source. Each shutter–filter pair forms a single sub-pixel. The sub-pixels are so small that when the display is viewed from even a short distance, the individual colors blend together to produce a single spot of color, a pixel. The shade of color is controlled by changing the relative intensity of the light passing through the sub-pixels.