Gray-scale with a tinge of blue color map.
BONE(M) returns an M-by-3 matrix containing a "bone" colormap.
BONE, by itself, is the same length as the current colormap.
For example, to reset the colormap of the current figure:
See also HSV , GRAY , HOT , COOL , COPPER , PINK , FLAG ,
COLORMAP , RGBPLOT .