To define the color or shading of object displayed on screen or printed on paper, color values are used, which are typically based on color models. Models may include a single color (such as for the grayscale model) or multiple colors. The RGB color model uses three colors (Red, Green and Blue), while the CMYK model uses four (Cyan, Magenta, Yellow and Black). For each color, a value ranging from 0, for 0% color intensity, to 255, for 100% color intensity, is used. If the Grayscale model is used, only a single value is required. For the RGB model, three values are used, while four are needed for the CMYK model. These values are stored in an array, which can store as many as four values.
Color arrays are primarily used internally by the PlanetPress Talk interpreter. However there are a handful of commands that expect a color array as an argument (setfillcolor for example).