With regards to HSV as a color model, the hue (H) component is better described as the angle within the RGB color wheel, where R is at 0 degrees, G is at 120 degrees, and B is at 240 degrees. This happens to roughly correspond with the sensitivity curves of the cones in the average human retina, and thus it does a good job of representing the entire human-visible spectrum. This is also a useful way to represent color models which are based on any three wavelengths, as well as to create an optimal mapping (of the false-color sense) between different color gamuts, particularly where the number of basis wavelengths differs between them.