Here's a copy of Ronald Thomas's standard reply -
1) Use "shade.rel.sh" to develop a pleasing "aspect"-like graphic image; it
looks like an aspect map, but its values are solely a function of graphics,
it is not data. (With a little experimentation, you can develop an image
that puts the "r.slope.aspect" generated aspect image to shame)
2) Use your new shade image in "d.his"; using only the 'hue' and
'intensity' options ; example:
d.his h_map=<whatever> i_map=<new.shade>
this will create a new image on your monitor; add a "o=<new.out>" to create
an actual raster layer (type in "d.his help" to get the correct syntax).