This color is used in all the shadows. In landscapes, in some
instances, it serves for use in the middle distance and foreground; the
light places should be retouched with yellow or gold. It is also used
for tree trunks, fences, and the like. In portraits it serves to color
the hair and eyes, and appears in the dark shadows of the drapery and
furniture. If the background is dark, a nice effect is produced by
tinting it a little with this color.