The position of an object represents the two color indices. The horizontal axis is V-B, blue color index [the difference in the magnitude of the object observed through a visual (green-yellow) and a blue filter], and the vertical axis is R-V, red color index (the difference in the magnitude between red and visual filters). Color (slightly enhanced) represents the hue of the object; albedo differences are not displayed. The size of a sphere illustrates the object’s size relative to others. For a few large objects, the diameter drawn represents the current estimates (for known albedos). For all the others, the diameter represents the absolute (V) magnitude of the object. For Phoebe, Triton, and Mars (yellow labels), size is not shown to scale.