Hue / Saturation Tool

Provides rotational hue and multiplicative saturation control. RGB color space can be imagined as a cube where the axes are the red, green, and blue color values. Hue changing works by rotating the color vector around the grayscale line, which is the straight line from black (0, 0, 0) to white (1, 1, 1). Saturation is implemented by scaling all color channel values either toward or away from the average color channel value.