In order to display colours that are missing in palettes with limited colour depth a technique called dithering is applied. It uses the limited spatial resolution of the eye. Pixels of two or three colours are placed next to each other in certain patterns so that, when looking from a distance, a colour seems to be displayed that is actually not contained in the palette. There are a variety of algorithms to do this. However, the result may be a coarse and grainy display. Artists like Roy Lichtenstein used this technique in some of their paintings.