axisAngleColorKey

Colorizes orientations according to their misorientation axis and misorientation angle in specimen coordinates with respect to some refererence orientation. The angle determines the saturation of the color, i.e., a misorientation angle of 0 corresponds to gray and the misorientation ange at maximum corresponds to fully saturated colors. The saturated color is determined by the misorientation axis. In the X-Y plane the colors circle through the rainbow colors and goes to white and black for z to +/-1.

The reference orientation may be single fixed orientation or a list of orientations. A typical example is to set the reference orientation as the mean orientation of the grain the pixel orientation belongs to.

Reference: Thomsen et al.: Quaternion-based disorientation coloring of orientation maps, 2017