HSV
A close relative of HSL, used in many colour pickers, with value or brightness as the third number.
Also: HSB, hue saturation value, hue saturation brightness
HSV describes a colour by hue, saturation and value, also called brightness. Hue is the same angle as in HSL. The difference is in the other two. In HSV, a value of 100 per cent gives the brightest version of the colour, and white is reached by lowering saturation to zero. Many colour pickers show HSV as a square with a hue slider beside it: move right for stronger colour, down for darker. It matches the way a painter might think of adding white or black to a pure pigment.