Like running, it can take place on a track or as a road race. The main competitions take place at the Summer Paralympics which wheelchair racing and athletics has been a part of since 1960. Competitors compete in specialized wheelchairs which allow the athletes to reach speeds of 30 km/h or more.
Hue is one of the main properties (called color appearance parameters) of a color, defined technically (in the CIECAM02 model), as the degree to which a stimulus can be described as similar to or different from stimuli that are described as red, green, blue, and yellow  (the unique hues).
What are primary colors? A common definition is that primary colors are the colors that can be used to make all other colors, and that the primary colors cannot be made by mixing any colors. Most elementary school instructors teach that red, yellow, and blue are the primary colors. All parts of this definition are either wrong or inadequate. First: there is no one set of colors that can produce all other colors. Almost any three or more colors can be mixed to produce all the other hues.